diff --git a/Signal/src/ViewControllers/ContactsViewHelper.m b/Signal/src/ViewControllers/ContactsViewHelper.m
index cfdc92ba5e..2d58f82bb7 100644
--- a/Signal/src/ViewControllers/ContactsViewHelper.m
+++ b/Signal/src/ViewControllers/ContactsViewHelper.m
@@ -5,6 +5,7 @@
 #import "ContactsViewHelper.h"
 #import "ContactTableViewCell.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSProfileManager.h"
 #import "Signal-Swift.h"
 #import <SignalServiceKit/Contact.h>
@@ -205,7 +206,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSArray<NSString *> *)searchTermsForSearchString:(NSString *)searchText
 {
-    return [[[searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
+    return [[[searchText ows_stripped]
         componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
         filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(NSString *_Nullable searchTerm,
                                         NSDictionary<NSString *, id> *_Nullable bindings) {
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h b/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h
index 20f83a0a61..0ba624c847 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h
+++ b/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h
@@ -43,6 +43,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSAttributedString *)attributedContactOrProfileNameForPhoneIdentifier:(NSString *)recipientId;
 
+#pragma mark - Caching
+
+- (NSCache *)cellMediaCache;
+
 @end
 
 #pragma mark -
@@ -54,9 +58,22 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic, nullable) ConversationViewItem *viewItem;
 
+// Cells are prefetched but expensive cells (e.g. media) should only load
+// when visible and unload when no longer visible.  Non-visible cells can
+// cache their contents on their ConversationViewItem, but that cache may
+// be evacuated before the cell becomes visible again.
+//
+// ConversationViewController also uses this property to evacuate the cell's
+// meda views when:
+//
+// * App enters background.
+// * Users enters another view (e.g. conversation settings view, call screen, etc.).
 @property (nonatomic) BOOL isCellVisible;
 
-- (void)loadForDisplay:(int)contentWidth;
+// The width of the collection view.
+@property (nonatomic) int contentWidth;
+
+- (void)loadForDisplay;
 
 - (CGSize)cellSizeForViewWidth:(int)viewWidth contentWidth:(int)contentWidth;
 
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.m b/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.m
index a168467bc9..ea9852c0aa 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.m
@@ -16,9 +16,10 @@ NS_ASSUME_NONNULL_BEGIN
     self.viewItem = nil;
     self.delegate = nil;
     self.isCellVisible = NO;
+    self.contentWidth = 0;
 }
 
-- (void)loadForDisplay:(int)contentWidth
+- (void)loadForDisplay
 {
     OWSFail(@"%@ This method should be overridden.", self.logTag);
 }
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.h b/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.h
index fc7465fbb0..7200788e33 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.h
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.h
@@ -15,7 +15,7 @@ NS_ASSUME_NONNULL_BEGIN
                         isIncoming:(BOOL)isIncoming
                           viewItem:(ConversationViewItem *)viewItem;
 
-- (void)createContentsForSize:(CGSize)viewSize;
+- (void)createContents;
 
 + (CGFloat)bubbleHeight;
 
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.m
index 11e0aa03ed..04a2f1e0a5 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.m
@@ -193,34 +193,45 @@ NS_ASSUME_NONNULL_BEGIN
     return (self.attachmentStream.isVoiceMessage || self.attachmentStream.sourceFilename.length < 1);
 }
 
-- (void)createContentsForSize:(CGSize)viewSize
+- (void)createContents
 {
     UIColor *textColor = [self audioTextColor];
 
     self.backgroundColor = self.bubbleBackgroundColor;
+    self.layoutMargins = UIEdgeInsetsZero;
 
+    // TODO: Verify that this layout works in RTL.
     const CGFloat kBubbleTailWidth = 6.f;
-    CGRect contentFrame = CGRectMake(self.isIncoming ? kBubbleTailWidth : 0.f,
-        self.audioIconVMargin,
-        viewSize.width - kBubbleTailWidth - self.audioIconHMargin,
-        viewSize.height - self.audioIconVMargin * 2);
 
-    CGRect iconFrame = CGRectMake((CGFloat)round(contentFrame.origin.x + self.audioIconHMargin),
-        (CGFloat)round(contentFrame.origin.y + (contentFrame.size.height - self.iconSize) * 0.5f),
-        self.iconSize,
-        self.iconSize);
-    _audioPlayPauseButton = [[UIButton alloc] initWithFrame:iconFrame];
-    _audioPlayPauseButton.enabled = NO;
-    [self addSubview:_audioPlayPauseButton];
+    UIView *contentView = [UIView containerView];
+    [self addSubview:contentView];
+    [contentView autoPinLeadingToSuperviewWithMargin:self.isIncoming ? kBubbleTailWidth : 0.f];
+    [contentView autoPinTrailingToSuperviewWithMargin:self.isIncoming ? 0.f : kBubbleTailWidth];
+    [contentView autoPinEdgeToSuperviewEdge:ALEdgeTop withInset:self.audioIconVMargin];
+    [contentView autoPinEdgeToSuperviewEdge:ALEdgeBottom withInset:self.audioIconVMargin];
+
+    _audioPlayPauseButton = [UIButton buttonWithType:UIButtonTypeCustom];
+    self.audioPlayPauseButton.enabled = NO;
+    [contentView addSubview:self.audioPlayPauseButton];
+    [self.audioPlayPauseButton autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:self.audioIconHMargin];
+    [self.audioPlayPauseButton autoVCenterInSuperview];
+    [self.audioPlayPauseButton autoSetDimension:ALDimensionWidth toSize:self.iconSize];
+    [self.audioPlayPauseButton autoSetDimension:ALDimensionHeight toSize:self.iconSize];
 
     const CGFloat kLabelHSpacing = self.audioIconHSpacing;
+
+    UIView *labelsView = [UIView containerView];
+    [contentView addSubview:labelsView];
+    [labelsView autoPinLeadingToTrailingOfView:self.audioPlayPauseButton margin:kLabelHSpacing];
+    [labelsView autoPinEdgeToSuperviewEdge:ALEdgeRight];
+    [labelsView autoVCenterInSuperview];
+
     const CGFloat kLabelVSpacing = 2;
     NSString *filename = self.attachmentStream.sourceFilename;
     if (!filename) {
         filename = [[self.attachmentStream filePath] lastPathComponent];
     }
-    NSString *topText = [[filename stringByDeletingPathExtension]
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *topText = [[filename stringByDeletingPathExtension] ows_stripped];
     if (topText.length < 1) {
         topText = [MIMETypeUtil fileExtensionForMIMEType:self.attachmentStream.contentType].uppercaseString;
     }
@@ -235,13 +246,18 @@ NS_ASSUME_NONNULL_BEGIN
     topLabel.textColor = [textColor colorWithAlphaComponent:0.85f];
     topLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     topLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(11.f, 13.f)];
-    [topLabel sizeToFit];
-    [self addSubview:topLabel];
+    [labelsView addSubview:topLabel];
+    [topLabel autoPinEdgeToSuperviewEdge:ALEdgeTop];
+    [topLabel autoPinWidthToSuperview];
 
+    const CGFloat kAudioProgressViewHeight = 12.f;
     AudioProgressView *audioProgressView = [AudioProgressView new];
     self.audioProgressView = audioProgressView;
     [self updateAudioProgressView];
-    [self addSubview:audioProgressView];
+    [labelsView addSubview:audioProgressView];
+    [audioProgressView autoPinWidthToSuperview];
+    [audioProgressView autoSetDimension:ALDimensionHeight toSize:kAudioProgressViewHeight];
+    [audioProgressView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:topLabel withOffset:kLabelVSpacing];
 
     UILabel *bottomLabel = [UILabel new];
     self.audioBottomLabel = bottomLabel;
@@ -249,25 +265,10 @@ NS_ASSUME_NONNULL_BEGIN
     bottomLabel.textColor = [textColor colorWithAlphaComponent:0.85f];
     bottomLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     bottomLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(11.f, 13.f)];
-    [bottomLabel sizeToFit];
-    [self addSubview:bottomLabel];
-
-    const CGFloat topLabelHeight = (CGFloat)ceil(topLabel.font.lineHeight);
-    const CGFloat kAudioProgressViewHeight = 12.f;
-    const CGFloat bottomLabelHeight = (CGFloat)ceil(bottomLabel.font.lineHeight);
-    CGRect labelsBounds = CGRectZero;
-    labelsBounds.origin.x = (CGFloat)round(iconFrame.origin.x + iconFrame.size.width + kLabelHSpacing);
-    labelsBounds.size.width = contentFrame.origin.x + contentFrame.size.width - labelsBounds.origin.x;
-    labelsBounds.size.height = topLabelHeight + kAudioProgressViewHeight + bottomLabelHeight + kLabelVSpacing * 2;
-    labelsBounds.origin.y
-        = (CGFloat)round(contentFrame.origin.y + (contentFrame.size.height - labelsBounds.size.height) * 0.5f);
-
-    CGFloat y = labelsBounds.origin.y;
-    topLabel.frame = CGRectMake(labelsBounds.origin.x, labelsBounds.origin.y, labelsBounds.size.width, topLabelHeight);
-    y += topLabelHeight + kLabelVSpacing;
-    audioProgressView.frame = CGRectMake(labelsBounds.origin.x, y, labelsBounds.size.width, kAudioProgressViewHeight);
-    y += kAudioProgressViewHeight + kLabelVSpacing;
-    bottomLabel.frame = CGRectMake(labelsBounds.origin.x, y, labelsBounds.size.width, bottomLabelHeight);
+    [labelsView addSubview:bottomLabel];
+    [bottomLabel autoPinWidthToSuperview];
+    [bottomLabel autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:audioProgressView withOffset:kLabelVSpacing];
+    [bottomLabel autoPinEdgeToSuperviewEdge:ALEdgeBottom];
 
     [self updateContents];
 }
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
index 5dcd6171e0..dfc21c6f15 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
@@ -87,7 +87,7 @@ NS_ASSUME_NONNULL_BEGIN
     return NSStringFromClass([self class]);
 }
 
-- (void)loadForDisplay:(int)contentWidth
+- (void)loadForDisplay
 {
     OWSAssert(self.viewItem);
     OWSAssert([self.viewItem.interaction isKindOfClass:[OWSContactOffersInteraction class]]);
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.h b/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.h
index f3b0957099..73b9bcaba0 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.h
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.h
@@ -10,7 +10,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithAttachment:(TSAttachmentStream *)attachmentStream isIncoming:(BOOL)isIncoming;
 
-- (void)createContentsForSize:(CGSize)viewSize;
+- (void)createContents;
 
 + (CGFloat)bubbleHeight;
 
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.m
index f6831a6fac..2c0d869108 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.m
@@ -3,6 +3,7 @@
 //
 
 #import "OWSGenericAttachmentView.h"
+#import "NSString+OWS.h"
 #import "UIColor+JSQMessages.h"
 #import "UIColor+OWS.h"
 #import "UIFont+OWS.h"
@@ -98,32 +99,43 @@ NS_ASSUME_NONNULL_BEGIN
     return [self.textColor blendWithColor:self.bubbleBackgroundColor alpha:alpha];
 }
 
-- (void)createContentsForSize:(CGSize)viewSize
+- (void)createContents
 {
     UIColor *textColor = (self.isIncoming ? [UIColor colorWithWhite:0.2 alpha:1.f] : [UIColor whiteColor]);
 
     self.backgroundColor = self.bubbleBackgroundColor;
+    self.layoutMargins = UIEdgeInsetsZero;
 
+    // TODO: Verify that this layout works in RTL.
     const CGFloat kBubbleTailWidth = 6.f;
-    CGRect contentFrame = CGRectMake(self.isIncoming ? kBubbleTailWidth : 0.f,
-        self.vMargin,
-        viewSize.width - kBubbleTailWidth - self.iconHMargin,
-        viewSize.height - self.vMargin * 2);
+
+    UIView *contentView = [UIView containerView];
+    [self addSubview:contentView];
+    [contentView autoPinLeadingToSuperviewWithMargin:self.isIncoming ? kBubbleTailWidth : 0.f];
+    [contentView autoPinTrailingToSuperviewWithMargin:self.isIncoming ? 0.f : kBubbleTailWidth];
+    [contentView autoPinEdgeToSuperviewEdge:ALEdgeTop withInset:self.vMargin];
+    [contentView autoPinEdgeToSuperviewEdge:ALEdgeBottom withInset:self.vMargin];
 
     UIImage *image = [UIImage imageNamed:@"generic-attachment-small"];
     OWSAssert(image);
     UIImageView *imageView = [UIImageView new];
-    CGRect iconFrame = CGRectMake(round(contentFrame.origin.x + self.iconHMargin),
-        round(contentFrame.origin.y + (contentFrame.size.height - self.iconSize) * 0.5f),
-        self.iconSize,
-        self.iconSize);
-    imageView.frame = iconFrame;
     imageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
     imageView.tintColor = self.bubbleBackgroundColor;
     imageView.backgroundColor
         = (self.isIncoming ? [UIColor colorWithRGBHex:0x9e9e9e] : [self foregroundColorWithOpacity:0.15f]);
     imageView.layer.cornerRadius = MIN(imageView.bounds.size.width, imageView.bounds.size.height) * 0.5f;
-    [self addSubview:imageView];
+    [contentView addSubview:imageView];
+    [imageView autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:self.iconHMargin];
+    [imageView autoVCenterInSuperview];
+    [imageView autoSetDimension:ALDimensionWidth toSize:self.iconSize];
+    [imageView autoSetDimension:ALDimensionHeight toSize:self.iconSize];
+
+    const CGFloat kLabelHSpacing = self.iconHSpacing;
+    UIView *labelsView = [UIView containerView];
+    [contentView addSubview:labelsView];
+    [labelsView autoPinLeadingToTrailingOfView:imageView margin:kLabelHSpacing];
+    [labelsView autoPinEdgeToSuperviewEdge:ALEdgeRight];
+    [labelsView autoVCenterInSuperview];
 
     NSString *filename = self.attachmentStream.sourceFilename;
     if (!filename) {
@@ -145,22 +157,13 @@ NS_ASSUME_NONNULL_BEGIN
     fileTypeLabel.font = [UIFont ows_mediumFontWithSize:20.f];
     fileTypeLabel.adjustsFontSizeToFitWidth = YES;
     fileTypeLabel.textAlignment = NSTextAlignmentCenter;
-    CGRect fileTypeLabelFrame = CGRectZero;
-    fileTypeLabelFrame.size = [fileTypeLabel sizeThatFits:CGSizeZero];
-    // This dimension depends on the space within the icon boundaries.
-    fileTypeLabelFrame.size.width = 15.f;
     // Center on icon.
-    fileTypeLabelFrame.origin.x
-        = round(iconFrame.origin.x + (iconFrame.size.width - fileTypeLabelFrame.size.width) * 0.5f);
-    fileTypeLabelFrame.origin.y
-        = round(iconFrame.origin.y + (iconFrame.size.height - fileTypeLabelFrame.size.height) * 0.5f);
-    fileTypeLabel.frame = fileTypeLabelFrame;
-    [self addSubview:fileTypeLabel];
+    [imageView addSubview:fileTypeLabel];
+    [imageView autoCenterInSuperview];
+    [imageView autoSetDimension:ALDimensionWidth toSize:15.f];
 
-    const CGFloat kLabelHSpacing = self.iconHSpacing;
     const CGFloat kLabelVSpacing = 2;
-    NSString *topText =
-        [self.attachmentStream.sourceFilename stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+    NSString *topText = [self.attachmentStream.sourceFilename ows_stripped];
     if (topText.length < 1) {
         topText = [MIMETypeUtil fileExtensionForMIMEType:self.attachmentStream.contentType].uppercaseString;
     }
@@ -172,8 +175,9 @@ NS_ASSUME_NONNULL_BEGIN
     topLabel.textColor = textColor;
     topLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     topLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(13.f, 15.f)];
-    [topLabel sizeToFit];
-    [self addSubview:topLabel];
+    [labelsView addSubview:topLabel];
+    [topLabel autoPinEdgeToSuperviewEdge:ALEdgeTop];
+    [topLabel autoPinWidthToSuperview];
 
     NSError *error;
     unsigned long long fileSize =
@@ -185,21 +189,10 @@ NS_ASSUME_NONNULL_BEGIN
     bottomLabel.textColor = [textColor colorWithAlphaComponent:0.85f];
     bottomLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     bottomLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(11.f, 13.f)];
-    [bottomLabel sizeToFit];
-    [self addSubview:bottomLabel];
-
-    CGRect topLabelFrame = CGRectZero;
-    topLabelFrame.size = topLabel.bounds.size;
-    topLabelFrame.origin.x = round(iconFrame.origin.x + iconFrame.size.width + kLabelHSpacing);
-    topLabelFrame.origin.y = round(contentFrame.origin.y
-        + (contentFrame.size.height - (topLabel.frame.size.height + bottomLabel.frame.size.height + kLabelVSpacing))
-            * 0.5f);
-    topLabelFrame.size.width = round((contentFrame.origin.x + contentFrame.size.width) - topLabelFrame.origin.x);
-    topLabel.frame = topLabelFrame;
-
-    CGRect bottomLabelFrame = topLabelFrame;
-    bottomLabelFrame.origin.y += topLabelFrame.size.height + kLabelVSpacing;
-    bottomLabel.frame = bottomLabelFrame;
+    [labelsView addSubview:bottomLabel];
+    [bottomLabel autoPinWidthToSuperview];
+    [bottomLabel autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:topLabel withOffset:kLabelVSpacing];
+    [bottomLabel autoPinEdgeToSuperviewEdge:ALEdgeBottom];
 }
 
 @end
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m
index 739b55c307..4a1db8aa8d 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m
@@ -207,7 +207,7 @@ NS_ASSUME_NONNULL_BEGIN
     return (TSMessage *)self.viewItem.interaction;
 }
 
-- (void)loadForDisplay:(int)contentWidth
+- (void)loadForDisplay
 {
     OWSAssert(self.viewItem);
     OWSAssert(self.viewItem.interaction);
@@ -220,7 +220,7 @@ NS_ASSUME_NONNULL_BEGIN
         = isIncoming ? [self.bubbleFactory incoming] : [self.bubbleFactory outgoing];
     self.bubbleImageView.image = bubbleImageData.messageBubbleImage;
 
-    [self updateDateHeader:contentWidth];
+    [self updateDateHeader];
     [self updateFooter];
 
     switch (self.cellType) {
@@ -243,7 +243,7 @@ NS_ASSUME_NONNULL_BEGIN
         case OWSMessageCellType_GenericAttachment: {
             self.attachmentView =
                 [[OWSGenericAttachmentView alloc] initWithAttachment:self.attachmentStream isIncoming:self.isIncoming];
-            [self.attachmentView createContentsForSize:self.bounds.size];
+            [self.attachmentView createContents];
             [self replaceBubbleWithView:self.attachmentView];
             [self addAttachmentUploadViewIfNecessary:self.attachmentView];
             break;
@@ -254,6 +254,8 @@ NS_ASSUME_NONNULL_BEGIN
         }
     }
 
+    [self ensureViewMediaState];
+
     //    dispatch_async(dispatch_get_main_queue(), ^{
     //        NSLog(@"---- %@", self.viewItem.interaction.debugDescription);
     //        NSLog(@"cell: %@", NSStringFromCGRect(self.frame));
@@ -263,8 +265,113 @@ NS_ASSUME_NONNULL_BEGIN
     //    });
 }
 
-- (void)updateDateHeader:(int)contentWidth
+// We now eagerly create out view hierarchy (to do this exactly once per cell usage)
+// but lazy-load any expensive media (photo, gif, etc.) used in those views. Note that
+// this lazy-load can fail, in which case we modify the view hierarchy to use an "error"
+// state. The didCellMediaFailToLoad reflects media load fails.
+- (nullable id)tryToLoadCellMedia:(nullable id (^)())loadCellMediaBlock
+                        mediaView:(UIView *)mediaView
+                         cacheKey:(NSString *)cacheKey
 {
+    OWSAssert(self.attachmentStream);
+    OWSAssert(mediaView);
+    OWSAssert(cacheKey);
+
+    if (self.viewItem.didCellMediaFailToLoad) {
+        return nil;
+    }
+
+    NSCache *cellMediaCache = self.delegate.cellMediaCache;
+    OWSAssert(cellMediaCache);
+
+    id _Nullable cellMedia = [cellMediaCache objectForKey:cacheKey];
+    if (cellMedia) {
+        DDLogVerbose(@"%@ cell media cache hit", self.logTag);
+        return cellMedia;
+    }
+    cellMedia = loadCellMediaBlock();
+    if (cellMedia) {
+        DDLogVerbose(@"%@ cell media cache miss", self.logTag);
+        [cellMediaCache setObject:cellMedia forKey:cacheKey];
+    } else {
+        DDLogError(@"%@ Failed to load cell media: %@", [self logTag], [self.attachmentStream mediaURL]);
+        self.viewItem.didCellMediaFailToLoad = YES;
+        [mediaView removeFromSuperview];
+        // TODO: We need to hide/remove the media view.
+        [self showAttachmentErrorView];
+    }
+    return cellMedia;
+}
+
+// We want to lazy-load expensive view contents and eagerly unload if the
+// cell is no longer visible.
+- (void)ensureViewMediaState
+{
+    if (!self.isCellVisible) {
+        // Eagerly unload.
+        self.stillImageView.image = nil;
+        self.animatedImageView.image = nil;
+        return;
+    }
+
+    switch (self.cellType) {
+        case OWSMessageCellType_StillImage: {
+            if (self.stillImageView.image) {
+                return;
+            }
+            self.stillImageView.image = [self tryToLoadCellMedia:^{
+                OWSAssert([self.attachmentStream isImage]);
+                return self.attachmentStream.image;
+            }
+                                                       mediaView:self.stillImageView
+                                                        cacheKey:self.attachmentStream.uniqueId];
+            break;
+        }
+        case OWSMessageCellType_AnimatedImage: {
+            if (self.animatedImageView.image) {
+                return;
+            }
+            self.animatedImageView.image = [self tryToLoadCellMedia:^{
+                OWSAssert([self.attachmentStream isAnimated]);
+
+                NSString *_Nullable filePath = [self.attachmentStream filePath];
+                YYImage *_Nullable animatedImage = nil;
+                if (filePath && [NSData ows_isValidImageAtPath:filePath]) {
+                    animatedImage = [YYImage imageWithContentsOfFile:filePath];
+                }
+                return animatedImage;
+            }
+                                                          mediaView:self.animatedImageView
+                                                           cacheKey:self.attachmentStream.uniqueId];
+            break;
+        }
+        case OWSMessageCellType_Video: {
+            if (self.stillImageView.image) {
+                return;
+            }
+            self.stillImageView.image = [self tryToLoadCellMedia:^{
+                OWSAssert([self.attachmentStream isVideo]);
+
+                return self.attachmentStream.image;
+            }
+                                                       mediaView:self.stillImageView
+                                                        cacheKey:self.attachmentStream.uniqueId];
+            break;
+        }
+        case OWSMessageCellType_TextMessage:
+        case OWSMessageCellType_OversizeTextMessage:
+        case OWSMessageCellType_GenericAttachment:
+        case OWSMessageCellType_DownloadingAttachment:
+        case OWSMessageCellType_Audio:
+            // Inexpensive cell types don't need to lazy-load or eagerly-unload.
+            break;
+    }
+}
+
+- (void)updateDateHeader
+{
+    OWSAssert(self.contentWidth > 0);
+
     static NSDateFormatter *dateHeaderDateFormatter = nil;
     static NSDateFormatter *dateHeaderTimeFormatter = nil;
     static dispatch_once_t onceToken;
@@ -312,7 +419,7 @@ NS_ASSUME_NONNULL_BEGIN
         self.dateHeaderConstraints = @[
             // Date headers should be visually centered within the conversation view,
             // so they need to extend outside the cell's boundaries.
-            [self.dateHeaderLabel autoSetDimension:ALDimensionWidth toSize:contentWidth],
+            [self.dateHeaderLabel autoSetDimension:ALDimensionWidth toSize:self.contentWidth],
             (self.isIncoming ? [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeLeading]
                              : [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeTrailing]),
             [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeTop],
@@ -452,14 +559,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(self.attachmentStream);
     OWSAssert([self.attachmentStream isImage]);
 
-    UIImage *_Nullable image = self.attachmentStream.image;
-    if (!image) {
-        DDLogError(@"%@ Could not load image: %@", [self logTag], [self.attachmentStream mediaURL]);
-        [self showAttachmentErrorView];
-        return;
-    }
-
-    self.stillImageView = [[UIImageView alloc] initWithImage:image];
+    self.stillImageView = [UIImageView new];
     // We need to specify a contentMode since the size of the image
     // might not match the aspect ratio of the view.
     self.stillImageView.contentMode = UIViewContentModeScaleAspectFill;
@@ -476,19 +576,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(self.attachmentStream);
     OWSAssert([self.attachmentStream isAnimated]);
 
-    NSString *_Nullable filePath = [self.attachmentStream filePath];
-    YYImage *_Nullable animatedImage = nil;
-    if (filePath && [NSData ows_isValidImageAtPath:filePath]) {
-        animatedImage = [YYImage imageWithContentsOfFile:filePath];
-    }
-    if (!animatedImage) {
-        DDLogError(@"%@ Could not load animated image: %@", [self logTag], [self.attachmentStream mediaURL]);
-        [self showAttachmentErrorView];
-        return;
-    }
-
     self.animatedImageView = [[YYAnimatedImageView alloc] init];
-    self.animatedImageView.image = animatedImage;
     // We need to specify a contentMode since the size of the image
     // might not match the aspect ratio of the view.
     self.animatedImageView.contentMode = UIViewContentModeScaleAspectFill;
@@ -505,7 +593,7 @@ NS_ASSUME_NONNULL_BEGIN
                                                                  isIncoming:self.isIncoming
                                                                    viewItem:self.viewItem];
     self.viewItem.lastAudioMessageView = self.audioMessageView;
-    [self.audioMessageView createContentsForSize:self.bounds.size];
+    [self.audioMessageView createContents];
     [self replaceBubbleWithView:self.audioMessageView];
     [self addAttachmentUploadViewIfNecessary:self.audioMessageView];
 }
@@ -515,16 +603,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(self.attachmentStream);
     OWSAssert([self.attachmentStream isVideo]);
 
-    //    CGSize size = [self mediaViewDisplaySize];
-
-    UIImage *_Nullable image = self.attachmentStream.image;
-    if (!image) {
-        DDLogError(@"%@ Could not load image: %@", [self logTag], [self.attachmentStream mediaURL]);
-        [self showAttachmentErrorView];
-        return;
-    }
-
-    self.stillImageView = [[UIImageView alloc] initWithImage:image];
+    self.stillImageView = [UIImageView new];
     // We need to specify a contentMode since the size of the image
     // might not match the aspect ratio of the view.
     self.stillImageView.contentMode = UIViewContentModeScaleAspectFill;
@@ -614,25 +693,11 @@ NS_ASSUME_NONNULL_BEGIN
     [self.payloadView updateMask];
 }
 
-//// TODO:
-//- (void)setFrame:(CGRect)frame {
-//    [super setFrame:frame];
-//
-//    DDLogError(@"setFrame: %@ %@ %@", self.viewItem.interaction.uniqueId, self.viewItem.interaction.description,
-//    NSStringFromCGRect(frame));
-//}
-//
-//// TODO:
-//- (void)setBounds:(CGRect)bounds {
-//    [super setBounds:bounds];
-//
-//    DDLogError(@"setBounds: %@ %@ %@", self.viewItem.interaction.uniqueId, self.viewItem.interaction.description,
-//    NSStringFromCGRect(bounds));
-//}
-
 - (void)showAttachmentErrorView
 {
-    // TODO: We could do a better job of indicating that the image could not be loaded.
+    OWSAssert(!self.customView);
+
+    // TODO: We could do a better job of indicating that the media could not be loaded.
     self.customView = [UIView new];
     self.customView.backgroundColor = [UIColor colorWithWhite:0.85f alpha:1.f];
     self.customView.userInteractionEnabled = NO;
@@ -860,6 +925,8 @@ NS_ASSUME_NONNULL_BEGIN
         return;
     }
 
+    [self ensureViewMediaState];
+
     if (isCellVisible) {
         if (self.message.shouldStartExpireTimer) {
             [self.expirationTimerView ensureAnimations];
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
index f0a1cdc68d..9b811758fb 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
@@ -85,7 +85,7 @@ NS_ASSUME_NONNULL_BEGIN
     return NSStringFromClass([self class]);
 }
 
-- (void)loadForDisplay:(int)contentWidth
+- (void)loadForDisplay
 {
     OWSAssert(self.viewItem);
 
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSUnreadIndicatorCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSUnreadIndicatorCell.m
index b078d29664..e97d32e08b 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSUnreadIndicatorCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSUnreadIndicatorCell.m
@@ -84,7 +84,7 @@ NS_ASSUME_NONNULL_BEGIN
     return NSStringFromClass([self class]);
 }
 
-- (void)loadForDisplay:(int)contentWidth
+- (void)loadForDisplay
 {
     OWSAssert(self.viewItem);
     OWSAssert([self.viewItem.interaction isKindOfClass:[TSUnreadIndicatorInteraction class]]);
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationCollectionView.m b/Signal/src/ViewControllers/ConversationView/ConversationCollectionView.m
index 5f02b528db..b973ae637f 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationCollectionView.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationCollectionView.m
@@ -57,6 +57,36 @@ NS_ASSUME_NONNULL_BEGIN
     [super setContentOffset:contentOffset];
 }
 
+- (void)reloadData
+{
+    DDLogVerbose(@"%@ reloadData", self.logTag);
+    [super reloadData];
+}
+
+- (void)reloadSections:(NSIndexSet *)sections
+{
+    DDLogVerbose(@"%@ reloadSections", self.logTag);
+    [super reloadSections:sections];
+}
+
+- (void)reloadItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths
+{
+    DDLogVerbose(@"%@ reloadItemsAtIndexPaths", self.logTag);
+    [super reloadItemsAtIndexPaths:indexPaths];
+}
+
+#pragma mark - Logging
+
++ (NSString *)logTag
+{
+    return [NSString stringWithFormat:@"[%@]", self.class];
+}
+
+- (NSString *)logTag
+{
+    return self.class.logTag;
+}
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m b/Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m
index 10be79193c..535ac1fbb5 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m
@@ -3,6 +3,7 @@
 //
 
 #import "ConversationInputTextView.h"
+#import "NSString+OWS.h"
 #import "Signal-Swift.h"
 
 NS_ASSUME_NONNULL_BEGIN
@@ -121,7 +122,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSString *)trimmedText
 {
-    return [self.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    return [self.text ows_stripped];
 }
 
 // TODO:
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index 591a216943..0455faf9bc 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -20,6 +20,7 @@
 #import "FingerprintViewController.h"
 #import "FullImageViewController.h"
 #import "NSAttributedString+OWS.h"
+#import "NSString+OWS.h"
 #import "NewGroupViewController.h"
 #import "OWSAudioAttachmentPlayer.h"
 #import "OWSContactOffersCell.h"
@@ -165,7 +166,8 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 @property (nonatomic, nullable) OWSAudioAttachmentPlayer *audioAttachmentPlayer;
 @property (nonatomic, nullable) NSUUID *voiceMessageUUID;
 
-@property (nonatomic) NSTimer *readTimer;
+@property (nonatomic, nullable) NSTimer *readTimer;
+@property (nonatomic) NSCache *cellMediaCache;
 @property (nonatomic) ConversationHeaderView *navigationBarTitleView;
 @property (nonatomic) UILabel *navigationBarTitleLabel;
 @property (nonatomic) UILabel *navigationBarSubtitleLabel;
@@ -392,6 +394,9 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     _isGroupConversation = [self.thread isKindOfClass:[TSGroupThread class]];
     _composeOnOpen = keyboardOnViewAppearing;
     _callOnOpen = callOnViewAppearing;
+    _cellMediaCache = [NSCache new];
+    // Cache the cell media for ~24 cells.
+    self.cellMediaCache.countLimit = 24;
 
     [self.uiDatabaseConnection beginLongLivedReadTransaction];
 
@@ -526,6 +531,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
         self.hasClearedUnreadMessagesIndicator = NO;
         [self.dynamicInteractions clearUnreadIndicatorState];
     }
+    [self.cellMediaCache removeAllObjects];
 }
 
 - (void)applicationWillResignActive:(NSNotification *)notification
@@ -943,6 +949,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 - (void)cancelReadTimer
 {
     [self.readTimer invalidate];
+    self.readTimer = nil;
 }
 
 - (void)viewDidAppear:(BOOL)animated
@@ -986,6 +993,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     [self saveDraft];
     [self markVisibleMessagesAsRead];
     [self cancelVoiceMemo];
+    [self.cellMediaCache removeAllObjects];
 
     self.isUserScrolling = NO;
 }
@@ -3630,7 +3638,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
         return;
     }
 
-    text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    text = [text ows_stripped];
 
     if (text.length < 1) {
         return;
@@ -4025,8 +4033,9 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     }
     cell.viewItem = viewItem;
     cell.delegate = self;
+    cell.contentWidth = self.layout.contentWidth;
 
-    [cell loadForDisplay:self.layout.contentWidth];
+    [cell loadForDisplay];
 
     return cell;
 }
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.h b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.h
index e48a1f12fd..03e29bdfc2 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.h
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.h
@@ -86,6 +86,10 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 - (nullable TSAttachmentPointer *)attachmentPointer;
 - (CGSize)contentSize;
 
+// We don't want to try to load the media for this item (if any)
+// if a load has previously failed.
+@property (nonatomic) BOOL didCellMediaFailToLoad;
+
 // TODO:
 //// Cells will request that this adapter clear its cached media views,
 //// but the adapter should only honor requests from the last cell to
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
index 863dc6ffe2..6ca452bc7f 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
@@ -3,6 +3,7 @@
 //
 
 #import "ConversationViewItem.h"
+#import "NSString+OWS.h"
 #import "OWSAudioMessageView.h"
 #import "OWSContactOffersCell.h"
 #import "OWSMessageCell.h"
@@ -274,14 +275,12 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     if (!displayableText) {
         // Only show up to 2kb of text.
         const NSUInteger kMaxTextDisplayLength = 2 * 1024;
-        text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+        text = [text ows_stripped];
         displayableText = [[DisplayableTextFilter new] displayableText:text];
         if (displayableText.length > kMaxTextDisplayLength) {
             // Trim whitespace before _AND_ after slicing the snipper from the string.
-            NSString *snippet =
-                [[[displayableText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
-                    substringWithRange:NSMakeRange(0, kMaxTextDisplayLength)]
-                    stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+            NSString *snippet = [
+                [[displayableText ows_stripped] substringWithRange:NSMakeRange(0, kMaxTextDisplayLength)] ows_stripped];
             displayableText = [NSString stringWithFormat:NSLocalizedString(@"OVERSIZE_TEXT_DISPLAY_FORMAT",
                                                              @"A display format for oversize text messages."),
                                         snippet];
diff --git a/Signal/src/ViewControllers/CountryCodeViewController.m b/Signal/src/ViewControllers/CountryCodeViewController.m
index 94771136b2..c202436cbd 100644
--- a/Signal/src/ViewControllers/CountryCodeViewController.m
+++ b/Signal/src/ViewControllers/CountryCodeViewController.m
@@ -3,6 +3,7 @@
 //
 
 #import "CountryCodeViewController.h"
+#import "NSString+OWS.h"
 #import "PhoneNumberUtil.h"
 #import "UIColor+OWS.h"
 #import "UIFont+OWS.h"
@@ -142,8 +143,7 @@
 
 - (void)searchTextDidChange
 {
-    NSString *searchText =
-        [self.searchBar.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchText = [self.searchBar.text ows_stripped];
 
     self.countryCodes = [PhoneNumberUtil countryCodesForSearchTerm:searchText];
 
diff --git a/Signal/src/ViewControllers/NewGroupViewController.m b/Signal/src/ViewControllers/NewGroupViewController.m
index 7e8d9babf3..9ff7b37299 100644
--- a/Signal/src/ViewControllers/NewGroupViewController.m
+++ b/Signal/src/ViewControllers/NewGroupViewController.m
@@ -9,6 +9,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSNavigationController.h"
 #import "OWSTableViewController.h"
@@ -515,8 +516,7 @@ const NSUInteger kNewGroupViewControllerAvatarWidth = 68;
 
 - (TSGroupModel *)makeGroup
 {
-    NSString *groupName = [self.groupNameTextField.text
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *groupName = [self.groupNameTextField.text ows_stripped];
     NSMutableArray<NSString *> *recipientIds = [self.memberRecipientIds.allObjects mutableCopy];
     [recipientIds addObject:[self.contactsViewHelper localNumber]];
     NSData *groupId = [SecurityUtils generateRandomBytes:16];
diff --git a/Signal/src/ViewControllers/ProfileViewController.m b/Signal/src/ViewControllers/ProfileViewController.m
index 4804e9625f..cda6d75a9a 100644
--- a/Signal/src/ViewControllers/ProfileViewController.m
+++ b/Signal/src/ViewControllers/ProfileViewController.m
@@ -6,6 +6,7 @@
 #import "AppDelegate.h"
 #import "AvatarViewHelper.h"
 #import "HomeViewController.h"
+#import "NSString+OWS.h"
 #import "OWSNavigationController.h"
 #import "OWSProfileManager.h"
 #import "Signal-Swift.h"
@@ -410,7 +411,7 @@ NSString *const kProfileView_LastPresentedDate = @"kProfileView_LastPresentedDat
 
 - (NSString *)normalizedProfileName
 {
-    return [self.nameTextField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    return [self.nameTextField.text ows_stripped];
 }
 
 - (void)updateProfileCompleted
diff --git a/Signal/src/ViewControllers/RegistrationViewController.m b/Signal/src/ViewControllers/RegistrationViewController.m
index e86d640798..86eb0409d3 100644
--- a/Signal/src/ViewControllers/RegistrationViewController.m
+++ b/Signal/src/ViewControllers/RegistrationViewController.m
@@ -6,6 +6,7 @@
 #import "CodeVerificationViewController.h"
 #import "CountryCodeViewController.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "PhoneNumber.h"
 #import "PhoneNumberUtil.h"
 #import "Signal-Swift.h"
@@ -280,8 +281,7 @@ NSString *const kKeychainKey_LastRegisteredPhoneNumber = @"kKeychainKey_LastRegi
 
 - (void)sendCodeAction
 {
-    NSString *phoneNumberText =
-        [_phoneNumberTextField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *phoneNumberText = [_phoneNumberTextField.text ows_stripped];
     if (phoneNumberText.length < 1) {
         [OWSAlerts
             showAlertWithTitle:NSLocalizedString(@"REGISTRATION_VIEW_NO_PHONE_NUMBER_ALERT_TITLE",
diff --git a/Signal/src/ViewControllers/SelectThreadViewController.m b/Signal/src/ViewControllers/SelectThreadViewController.m
index 268ffc1ca0..a16fb5df5a 100644
--- a/Signal/src/ViewControllers/SelectThreadViewController.m
+++ b/Signal/src/ViewControllers/SelectThreadViewController.m
@@ -7,6 +7,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSContactsSearcher.h"
 #import "OWSTableViewController.h"
@@ -223,8 +224,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     NSArray<TSThread *> *threads = self.threadViewHelper.threads;
 
-    NSString *searchTerm =
-        [[self.searchBar text] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchTerm = [[self.searchBar text] ows_stripped];
 
     if ([searchTerm isEqualToString:@""]) {
         return threads;
diff --git a/Signal/src/ViewControllers/SendExternalFileViewController.m b/Signal/src/ViewControllers/SendExternalFileViewController.m
index ad31813b81..264a18539c 100644
--- a/Signal/src/ViewControllers/SendExternalFileViewController.m
+++ b/Signal/src/ViewControllers/SendExternalFileViewController.m
@@ -4,6 +4,7 @@
 
 #import "SendExternalFileViewController.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "Signal-Swift.h"
 #import "ThreadUtil.h"
 #import "UIColor+OWS.h"
@@ -141,8 +142,7 @@ NS_ASSUME_NONNULL_BEGIN
     // TODO: If we reuse this VC, for example to offer a "forward attachment to other thread",
     //       feature, this assumption would no longer apply.
     OWSAssert(self.attachment);
-    NSString *filename =
-        [self.attachment.sourceFilename stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+    NSString *filename = [self.attachment.sourceFilename ows_stripped];
     OWSAssert(filename.length > 0);
     const NSUInteger kMaxFilenameLength = 20;
     if (filename.length > kMaxFilenameLength) {
diff --git a/Signal/src/ViewControllers/UpdateGroupViewController.m b/Signal/src/ViewControllers/UpdateGroupViewController.m
index eaced2e568..63471c2d0f 100644
--- a/Signal/src/ViewControllers/UpdateGroupViewController.m
+++ b/Signal/src/ViewControllers/UpdateGroupViewController.m
@@ -9,6 +9,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSNavigationController.h"
 #import "OWSTableViewController.h"
@@ -196,8 +197,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     UITextField *groupNameTextField = [UITextField new];
     _groupNameTextField = groupNameTextField;
-    self.groupNameTextField.text = [self.thread.groupModel.groupName
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    self.groupNameTextField.text = [self.thread.groupModel.groupName ows_stripped];
     groupNameTextField.textColor = [UIColor blackColor];
     groupNameTextField.font = [UIFont ows_dynamicTypeTitle2Font];
     groupNameTextField.placeholder
@@ -373,8 +373,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     OWSAssert(self.conversationSettingsViewDelegate);
 
-    NSString *groupName = [self.groupNameTextField.text
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *groupName = [self.groupNameTextField.text ows_stripped];
     TSGroupModel *groupModel = [[TSGroupModel alloc] initWithTitle:groupName
                                                          memberIds:[self.memberRecipientIds.allObjects mutableCopy]
                                                              image:self.groupAvatar
diff --git a/Signal/src/contact/OWSContactsSearcher.m b/Signal/src/contact/OWSContactsSearcher.m
index f776e444d0..774f1038c8 100644
--- a/Signal/src/contact/OWSContactsSearcher.m
+++ b/Signal/src/contact/OWSContactsSearcher.m
@@ -3,6 +3,7 @@
 //
 
 #import "OWSContactsSearcher.h"
+#import "NSString+OWS.h"
 #import <SignalServiceKit/PhoneNumber.h>
 
 @interface OWSContactsSearcher ()
@@ -22,7 +23,7 @@
 }
 
 - (NSArray<Contact *> *)filterWithString:(NSString *)string {
-    NSString *searchTerm = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchTerm = [string ows_stripped];
 
     if ([searchTerm isEqualToString:@""]) {
         return self.contacts;
diff --git a/Signal/src/environment/NotificationsManager.m b/Signal/src/environment/NotificationsManager.m
index 30a9ad50ef..e5315b0f81 100644
--- a/Signal/src/environment/NotificationsManager.m
+++ b/Signal/src/environment/NotificationsManager.m
@@ -4,6 +4,7 @@
 
 #import "NotificationsManager.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSPreferences.h"
 #import "PushManager.h"
@@ -272,8 +273,7 @@ NSString *const kNotificationsManagerNewMesssageSoundName = @"NewMessage.aifc";
         BOOL shouldPlaySound = [self shouldPlaySoundForNotification];
 
         NSString *senderName = [contactsManager displayNameForPhoneIdentifier:message.authorId];
-        NSString *groupName =
-            [thread.name stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+        NSString *groupName = [thread.name ows_stripped];
         if (groupName.length < 1) {
             groupName = [MessageStrings newGroupDefaultTitle];
         }