diff --git a/README.md b/README.md
index 19d9f10..a2f2703 100644
--- a/README.md
+++ b/README.md
@@ -1055,6 +1055,11 @@ gog slides list-slides <presentationId>
 gog slides add-slide <presentationId> ./slide.png --notes "Speaker notes"
 gog slides update-notes <presentationId> <slideId> --notes "Updated notes"
 gog slides replace-slide <presentationId> <slideId> ./new-slide.png --notes "New notes"
+gog slides insert-text <presentationId> <objectId> "Text to insert"
+gog slides insert-text <presentationId> <objectId> - < long-content.md
+gog slides insert-text <presentationId> <objectId> "New body" --replace
+gog slides replace-text <presentationId> "{{name}}" "Acme Corp"
+gog slides replace-text <presentationId> "TODO" "DONE" --match-case --page <slideId1> --page <slideId2>
 
 # Sheets
 gog sheets copy <spreadsheetId> "My Sheet Copy"
@@ -1474,6 +1479,32 @@ gog slides thumbnail <presentationId> <slideId> --output ./slide.png
 
 # Control thumbnail size and format
 gog slides thumbnail <presentationId> <slideId> --size medium --format jpeg --output ./slide.jpg
+
+# Insert text into an existing text-capable element (shape or table cell)
+gog slides insert-text <presentationId> <objectId> "Hello, world"
+
+# Insert at a specific position in the element's existing text
+gog slides insert-text <presentationId> <objectId> " (inserted)" --insertion-index 12
+
+# Replace the element's existing text wholesale (DeleteText + InsertText in one batch)
+gog slides insert-text <presentationId> <objectId> "Brand-new body copy" --replace
+
+# Read long content from stdin
+cat long-content.md | gog slides insert-text <presentationId> <objectId> -
+
+# Preview the batchUpdate request body without executing it
+gog slides insert-text <presentationId> <objectId> "demo" --replace --dry-run
+
+# Find-and-replace across the whole deck
+gog slides replace-text <presentationId> "{{customer_name}}" "Acme Corp"
+
+# Case-sensitive match, restricted to specific slides
+gog slides replace-text <presentationId> "TODO" "DONE" \
+  --match-case \
+  --page <slideId1> --page <slideId2>
+
+# Preview the replace request without executing it
+gog slides replace-text <presentationId> "old" "new" --dry-run
 ```
 
 ## Output Formats
diff --git a/internal/cmd/slides.go b/internal/cmd/slides.go
index f6d0088..e2d8873 100644
--- a/internal/cmd/slides.go
+++ b/internal/cmd/slides.go
@@ -33,6 +33,8 @@ type SlidesCmd struct {
 	Thumbnail          SlidesThumbnailCmd          `cmd:"" name:"thumbnail" aliases:"thumb" help:"Get or download a rendered thumbnail for a slide"`
 	UpdateNotes        SlidesUpdateNotesCmd        `cmd:"" name:"update-notes" help:"Update speaker notes on an existing slide"`
 	ReplaceSlide       SlidesReplaceSlideCmd       `cmd:"" name:"replace-slide" help:"Replace the image on an existing slide in-place"`
+	InsertText         SlidesInsertTextCmd         `cmd:"" name:"insert-text" help:"Insert text into an existing page element (shape or table) by objectId"`
+	ReplaceText        SlidesReplaceTextCmd        `cmd:"" name:"replace-text" help:"Find-and-replace text across a presentation"`
 }
 
 type SlidesExportCmd struct {
diff --git a/internal/cmd/slides_insert_text.go b/internal/cmd/slides_insert_text.go
new file mode 100644
index 0000000..125bb2a
--- /dev/null
+++ b/internal/cmd/slides_insert_text.go
@@ -0,0 +1,123 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"google.golang.org/api/slides/v1"
+
+	"github.com/steipete/gogcli/internal/outfmt"
+	"github.com/steipete/gogcli/internal/ui"
+)
+
+// SlidesInsertTextCmd inserts text into an existing text-capable page element.
+// It is a thin wrapper around presentations.batchUpdate with an InsertTextRequest
+// (optionally preceded by a DeleteText request when --replace is set).
+type SlidesInsertTextCmd struct {
+	PresentationID string `arg:"" name:"presentationId" help:"Presentation ID"`
+	ObjectID       string `arg:"" name:"objectId" help:"Page element object ID (shape or table) to insert text into"`
+	Text           string `arg:"" name:"text" help:"Text to insert (use '-' to read from stdin)"`
+	InsertionIndex int64  `name:"insertion-index" help:"Zero-based index where text is inserted within the element's existing text" default:"0"`
+	Replace        bool   `name:"replace" help:"Clear existing text in the element before inserting (emits DeleteText + InsertText in the same batch)"`
+}
+
+// Run executes the insert-text command.
+func (c *SlidesInsertTextCmd) Run(ctx context.Context, flags *RootFlags) error {
+	u := ui.FromContext(ctx)
+
+	presentationID := strings.TrimSpace(c.PresentationID)
+	if presentationID == "" {
+		return usage("empty presentationId")
+	}
+	objectID := strings.TrimSpace(c.ObjectID)
+	if objectID == "" {
+		return usage("empty objectId")
+	}
+
+	// Resolve text: '-' means read from stdin.
+	text := c.Text
+	if text == "-" {
+		data, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			return fmt.Errorf("read text from stdin: %w", err)
+		}
+		text = string(data)
+	}
+
+	// Build the batchUpdate request body.
+	var requests []*slides.Request
+	if c.Replace {
+		requests = append(requests, &slides.Request{
+			DeleteText: &slides.DeleteTextRequest{
+				ObjectId: objectID,
+				TextRange: &slides.Range{
+					Type: "ALL",
+				},
+			},
+		})
+	}
+	requests = append(requests, &slides.Request{
+		InsertText: &slides.InsertTextRequest{
+			ObjectId:       objectID,
+			Text:           text,
+			InsertionIndex: c.InsertionIndex,
+		},
+	})
+
+	body := &slides.BatchUpdatePresentationRequest{Requests: requests}
+
+	// Dry-run: print the request body we would send and exit without calling the API.
+	if flags != nil && flags.DryRun {
+		return writeSlidesBatchUpdateDryRun(ctx, body)
+	}
+
+	account, err := requireAccount(flags)
+	if err != nil {
+		return err
+	}
+
+	slidesSvc, err := newSlidesService(ctx, account)
+	if err != nil {
+		return err
+	}
+
+	resp, err := slidesSvc.Presentations.BatchUpdate(presentationID, body).Context(ctx).Do()
+	if err != nil {
+		return fmt.Errorf("insert text: %w", err)
+	}
+
+	if outfmt.IsJSON(ctx) {
+		return outfmt.WriteJSON(ctx, os.Stdout, resp)
+	}
+
+	revisionID := ""
+	if resp != nil && resp.WriteControl != nil {
+		revisionID = resp.WriteControl.RequiredRevisionId
+	}
+	replies := 0
+	if resp != nil {
+		replies = len(resp.Replies)
+	}
+	u.Out().Printf("ok | revisionId=%s | replies=%d", revisionID, replies)
+	return nil
+}
+
+// writeSlidesBatchUpdateDryRun serializes a BatchUpdatePresentationRequest to
+// stdout as pretty JSON. Used by slides commands that honor --dry-run.
+func writeSlidesBatchUpdateDryRun(ctx context.Context, body *slides.BatchUpdatePresentationRequest) error {
+	if body == nil {
+		return errors.New("nil batch update request")
+	}
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(body); err != nil {
+		return fmt.Errorf("encode dry-run request: %w", err)
+	}
+	_ = ctx // reserved for future use (e.g., UI-aware formatting)
+	return nil
+}
diff --git a/internal/cmd/slides_insert_text_test.go b/internal/cmd/slides_insert_text_test.go
new file mode 100644
index 0000000..5890596
--- /dev/null
+++ b/internal/cmd/slides_insert_text_test.go
@@ -0,0 +1,279 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+
+	"google.golang.org/api/option"
+	"google.golang.org/api/slides/v1"
+
+	"github.com/steipete/gogcli/internal/ui"
+)
+
+// mockSlidesBatchUpdateServer spins up an httptest.Server that captures the
+// batchUpdate request body and returns a canned BatchUpdatePresentationResponse.
+// Tests can inspect captured requests via the returned pointer.
+func mockSlidesBatchUpdateServer(
+	t *testing.T,
+	captured *[]*slides.Request,
+	response map[string]any,
+) *httptest.Server {
+	t.Helper()
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		if strings.HasSuffix(r.URL.Path, ":batchUpdate") && r.Method == http.MethodPost {
+			var req slides.BatchUpdatePresentationRequest
+			if err := json.NewDecoder(r.Body).Decode(&req); err == nil {
+				*captured = req.Requests
+			}
+			_ = json.NewEncoder(w).Encode(response)
+			return
+		}
+		http.NotFound(w, r)
+	}))
+	return srv
+}
+
+func newSlidesServiceFromServer(t *testing.T, srv *httptest.Server) *slides.Service {
+	t.Helper()
+	svc, err := slides.NewService(context.Background(),
+		option.WithoutAuthentication(),
+		option.WithHTTPClient(srv.Client()),
+		option.WithEndpoint(srv.URL+"/"),
+	)
+	if err != nil {
+		t.Fatalf("slides.NewService: %v", err)
+	}
+	return svc
+}
+
+func TestSlidesInsertText(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	var captured []*slides.Request
+	srv := mockSlidesBatchUpdateServer(t, &captured, map[string]any{
+		"presentationId": "pres1",
+		"replies":        []any{map[string]any{}},
+		"writeControl":   map[string]any{"requiredRevisionId": "rev-123"},
+	})
+	defer srv.Close()
+
+	svc := newSlidesServiceFromServer(t, srv)
+	newSlidesService = func(context.Context, string) (*slides.Service, error) { return svc, nil }
+
+	flags := &RootFlags{Account: "a@b.com"}
+
+	out := captureStdout(t, func() {
+		u, uiErr := ui.New(ui.Options{Stdout: os.Stdout, Stderr: io.Discard, Color: "never"})
+		if uiErr != nil {
+			t.Fatalf("ui.New: %v", uiErr)
+		}
+		ctx := ui.WithUI(context.Background(), u)
+
+		cmd := &SlidesInsertTextCmd{
+			PresentationID: "pres1",
+			ObjectID:       "shape_1",
+			Text:           "hello world",
+			InsertionIndex: 3,
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	if !strings.Contains(out, "ok | revisionId=rev-123 | replies=1") {
+		t.Errorf("expected plain confirmation with revisionId and replies, got: %q", out)
+	}
+	if len(captured) != 1 {
+		t.Fatalf("expected 1 request in batch, got %d", len(captured))
+	}
+	if captured[0].InsertText == nil {
+		t.Fatal("expected InsertText request")
+	}
+	if captured[0].InsertText.Text != "hello world" {
+		t.Errorf("expected text %q, got %q", "hello world", captured[0].InsertText.Text)
+	}
+	if captured[0].InsertText.ObjectId != "shape_1" {
+		t.Errorf("expected objectId shape_1, got %q", captured[0].InsertText.ObjectId)
+	}
+	if captured[0].InsertText.InsertionIndex != 3 {
+		t.Errorf("expected insertionIndex 3, got %d", captured[0].InsertText.InsertionIndex)
+	}
+}
+
+func TestSlidesInsertText_ReplaceEmitsDeleteThenInsert(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	var captured []*slides.Request
+	srv := mockSlidesBatchUpdateServer(t, &captured, map[string]any{
+		"presentationId": "pres1",
+		"replies":        []any{map[string]any{}, map[string]any{}},
+	})
+	defer srv.Close()
+
+	svc := newSlidesServiceFromServer(t, srv)
+	newSlidesService = func(context.Context, string) (*slides.Service, error) { return svc, nil }
+
+	flags := &RootFlags{Account: "a@b.com"}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	_ = captureStdout(t, func() {
+		cmd := &SlidesInsertTextCmd{
+			PresentationID: "pres1",
+			ObjectID:       "shape_1",
+			Text:           "replacement",
+			Replace:        true,
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	if len(captured) != 2 {
+		t.Fatalf("expected 2 requests (DeleteText + InsertText), got %d", len(captured))
+	}
+	if captured[0].DeleteText == nil {
+		t.Error("expected first request to be DeleteText")
+	} else if captured[0].DeleteText.TextRange == nil || captured[0].DeleteText.TextRange.Type != "ALL" {
+		t.Errorf("expected DeleteText TextRange.Type=ALL, got %+v", captured[0].DeleteText.TextRange)
+	}
+	if captured[1].InsertText == nil {
+		t.Error("expected second request to be InsertText")
+	} else if captured[1].InsertText.Text != "replacement" {
+		t.Errorf("expected inserted text %q, got %q", "replacement", captured[1].InsertText.Text)
+	}
+}
+
+func TestSlidesInsertText_StdinDash(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	var captured []*slides.Request
+	srv := mockSlidesBatchUpdateServer(t, &captured, map[string]any{
+		"presentationId": "pres1",
+		"replies":        []any{map[string]any{}},
+	})
+	defer srv.Close()
+
+	svc := newSlidesServiceFromServer(t, srv)
+	newSlidesService = func(context.Context, string) (*slides.Service, error) { return svc, nil }
+
+	// Pipe text into stdin.
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("pipe: %v", err)
+	}
+	origStdin := os.Stdin
+	os.Stdin = r
+	t.Cleanup(func() { os.Stdin = origStdin })
+
+	const piped = "from-stdin content\nline 2\n"
+	go func() {
+		_, _ = w.Write([]byte(piped))
+		_ = w.Close()
+	}()
+
+	flags := &RootFlags{Account: "a@b.com"}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	_ = captureStdout(t, func() {
+		cmd := &SlidesInsertTextCmd{
+			PresentationID: "pres1",
+			ObjectID:       "shape_1",
+			Text:           "-",
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	if len(captured) != 1 || captured[0].InsertText == nil {
+		t.Fatalf("expected single InsertText request, got %+v", captured)
+	}
+	if captured[0].InsertText.Text != piped {
+		t.Errorf("expected piped text %q, got %q", piped, captured[0].InsertText.Text)
+	}
+}
+
+func TestSlidesInsertText_DryRunNoAPICall(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	newSlidesService = func(context.Context, string) (*slides.Service, error) {
+		t.Fatal("slides service should not be created during dry-run")
+		return nil, context.Canceled
+	}
+
+	flags := &RootFlags{Account: "a@b.com", DryRun: true}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	out := captureStdout(t, func() {
+		cmd := &SlidesInsertTextCmd{
+			PresentationID: "pres1",
+			ObjectID:       "shape_1",
+			Text:           "dry",
+			Replace:        true,
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	var body slides.BatchUpdatePresentationRequest
+	if err := json.Unmarshal([]byte(out), &body); err != nil {
+		t.Fatalf("dry-run output should be valid JSON BatchUpdatePresentationRequest: %v\nout=%s", err, out)
+	}
+	if len(body.Requests) != 2 {
+		t.Fatalf("expected 2 requests in dry-run body, got %d", len(body.Requests))
+	}
+	if body.Requests[0].DeleteText == nil || body.Requests[1].InsertText == nil {
+		t.Errorf("expected DeleteText then InsertText in dry-run body, got %+v", body.Requests)
+	}
+}
+
+func TestSlidesInsertText_EmptyObjectID(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	newSlidesService = func(context.Context, string) (*slides.Service, error) {
+		t.Fatal("slides service should not be created")
+		return nil, context.Canceled
+	}
+
+	flags := &RootFlags{Account: "a@b.com"}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	cmd := &SlidesInsertTextCmd{
+		PresentationID: "pres1",
+		ObjectID:       "",
+		Text:           "something",
+	}
+	err := cmd.Run(ctx, flags)
+	if err == nil || !strings.Contains(err.Error(), "empty objectId") {
+		t.Fatalf("expected empty objectId error, got: %v", err)
+	}
+}
diff --git a/internal/cmd/slides_replace_text.go b/internal/cmd/slides_replace_text.go
new file mode 100644
index 0000000..d7898ea
--- /dev/null
+++ b/internal/cmd/slides_replace_text.go
@@ -0,0 +1,99 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"google.golang.org/api/slides/v1"
+
+	"github.com/steipete/gogcli/internal/outfmt"
+	"github.com/steipete/gogcli/internal/ui"
+)
+
+// SlidesReplaceTextCmd performs a find-and-replace across a presentation.
+// It is a thin wrapper around presentations.batchUpdate with a single
+// ReplaceAllTextRequest.
+type SlidesReplaceTextCmd struct {
+	PresentationID string   `arg:"" name:"presentationId" help:"Presentation ID"`
+	Find           string   `arg:"" name:"find" help:"Substring to find"`
+	Replacement    string   `arg:"" name:"replacement" help:"Replacement text"`
+	MatchCase      bool     `name:"match-case" help:"Case-sensitive match (default: false)"`
+	Pages          []string `name:"page" help:"Restrict replacement to specific slide object IDs (repeatable)"`
+}
+
+// Run executes the replace-text command.
+func (c *SlidesReplaceTextCmd) Run(ctx context.Context, flags *RootFlags) error {
+	u := ui.FromContext(ctx)
+
+	presentationID := strings.TrimSpace(c.PresentationID)
+	if presentationID == "" {
+		return usage("empty presentationId")
+	}
+	if c.Find == "" {
+		return usage("empty find text")
+	}
+
+	// Build the batchUpdate request body.
+	req := &slides.ReplaceAllTextRequest{
+		ContainsText: &slides.SubstringMatchCriteria{
+			Text:      c.Find,
+			MatchCase: c.MatchCase,
+		},
+		ReplaceText: c.Replacement,
+	}
+	if len(c.Pages) > 0 {
+		// Preserve order and trim whitespace on each page id.
+		pages := make([]string, 0, len(c.Pages))
+		for _, p := range c.Pages {
+			if p = strings.TrimSpace(p); p != "" {
+				pages = append(pages, p)
+			}
+		}
+		req.PageObjectIds = pages
+	}
+
+	body := &slides.BatchUpdatePresentationRequest{
+		Requests: []*slides.Request{{ReplaceAllText: req}},
+	}
+
+	// Dry-run: print the request body we would send and exit without calling the API.
+	if flags != nil && flags.DryRun {
+		return writeSlidesBatchUpdateDryRun(ctx, body)
+	}
+
+	account, err := requireAccount(flags)
+	if err != nil {
+		return err
+	}
+
+	slidesSvc, err := newSlidesService(ctx, account)
+	if err != nil {
+		return err
+	}
+
+	resp, err := slidesSvc.Presentations.BatchUpdate(presentationID, body).Context(ctx).Do()
+	if err != nil {
+		return fmt.Errorf("replace text: %w", err)
+	}
+
+	if outfmt.IsJSON(ctx) {
+		return outfmt.WriteJSON(ctx, os.Stdout, resp)
+	}
+
+	var replaced int64
+	if resp != nil {
+		for _, r := range resp.Replies {
+			if r != nil && r.ReplaceAllText != nil {
+				replaced += r.ReplaceAllText.OccurrencesChanged
+			}
+		}
+	}
+	revisionID := ""
+	if resp != nil && resp.WriteControl != nil {
+		revisionID = resp.WriteControl.RequiredRevisionId
+	}
+	u.Out().Printf("ok | revisionId=%s | replaced=%d", revisionID, replaced)
+	return nil
+}
diff --git a/internal/cmd/slides_replace_text_test.go b/internal/cmd/slides_replace_text_test.go
new file mode 100644
index 0000000..28daff5
--- /dev/null
+++ b/internal/cmd/slides_replace_text_test.go
@@ -0,0 +1,204 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"google.golang.org/api/slides/v1"
+
+	"github.com/steipete/gogcli/internal/ui"
+)
+
+func TestSlidesReplaceText(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	var captured []*slides.Request
+	srv := mockSlidesBatchUpdateServer(t, &captured, map[string]any{
+		"presentationId": "pres1",
+		"replies": []any{
+			map[string]any{
+				"replaceAllText": map[string]any{"occurrencesChanged": 4},
+			},
+		},
+		"writeControl": map[string]any{"requiredRevisionId": "rev-abc"},
+	})
+	defer srv.Close()
+
+	svc := newSlidesServiceFromServer(t, srv)
+	newSlidesService = func(context.Context, string) (*slides.Service, error) { return svc, nil }
+
+	flags := &RootFlags{Account: "a@b.com"}
+
+	out := captureStdout(t, func() {
+		u, uiErr := ui.New(ui.Options{Stdout: os.Stdout, Stderr: io.Discard, Color: "never"})
+		if uiErr != nil {
+			t.Fatalf("ui.New: %v", uiErr)
+		}
+		ctx := ui.WithUI(context.Background(), u)
+
+		cmd := &SlidesReplaceTextCmd{
+			PresentationID: "pres1",
+			Find:           "oldName",
+			Replacement:    "newName",
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	if !strings.Contains(out, "ok | revisionId=rev-abc | replaced=4") {
+		t.Errorf("expected confirmation with revisionId + replaced count, got: %q", out)
+	}
+	if len(captured) != 1 {
+		t.Fatalf("expected 1 request in batch, got %d", len(captured))
+	}
+	if captured[0].ReplaceAllText == nil {
+		t.Fatal("expected ReplaceAllText request")
+	}
+	if captured[0].ReplaceAllText.ContainsText == nil {
+		t.Fatal("expected ContainsText set on request")
+	}
+	if captured[0].ReplaceAllText.ContainsText.Text != "oldName" {
+		t.Errorf("expected find text %q, got %q", "oldName", captured[0].ReplaceAllText.ContainsText.Text)
+	}
+	if captured[0].ReplaceAllText.ContainsText.MatchCase {
+		t.Error("expected MatchCase=false by default")
+	}
+	if captured[0].ReplaceAllText.ReplaceText != "newName" {
+		t.Errorf("expected replacement %q, got %q", "newName", captured[0].ReplaceAllText.ReplaceText)
+	}
+	if len(captured[0].ReplaceAllText.PageObjectIds) != 0 {
+		t.Errorf("expected no PageObjectIds, got %+v", captured[0].ReplaceAllText.PageObjectIds)
+	}
+}
+
+func TestSlidesReplaceText_MatchCaseAndPages(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	var captured []*slides.Request
+	srv := mockSlidesBatchUpdateServer(t, &captured, map[string]any{
+		"presentationId": "pres1",
+		"replies": []any{
+			map[string]any{"replaceAllText": map[string]any{"occurrencesChanged": 1}},
+		},
+	})
+	defer srv.Close()
+
+	svc := newSlidesServiceFromServer(t, srv)
+	newSlidesService = func(context.Context, string) (*slides.Service, error) { return svc, nil }
+
+	flags := &RootFlags{Account: "a@b.com"}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	_ = captureStdout(t, func() {
+		cmd := &SlidesReplaceTextCmd{
+			PresentationID: "pres1",
+			Find:           "FooBar",
+			Replacement:    "BazQux",
+			MatchCase:      true,
+			Pages:          []string{"slide_1", "slide_2"},
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	if len(captured) != 1 || captured[0].ReplaceAllText == nil {
+		t.Fatalf("expected 1 ReplaceAllText request, got %+v", captured)
+	}
+	if !captured[0].ReplaceAllText.ContainsText.MatchCase {
+		t.Error("expected MatchCase=true")
+	}
+	got := captured[0].ReplaceAllText.PageObjectIds
+	want := []string{"slide_1", "slide_2"}
+	if len(got) != len(want) {
+		t.Fatalf("expected %d pageObjectIds, got %d (%+v)", len(want), len(got), got)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("pageObjectIds[%d] = %q, want %q", i, got[i], want[i])
+		}
+	}
+}
+
+func TestSlidesReplaceText_DryRunNoAPICall(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	newSlidesService = func(context.Context, string) (*slides.Service, error) {
+		t.Fatal("slides service should not be created during dry-run")
+		return nil, context.Canceled
+	}
+
+	flags := &RootFlags{Account: "a@b.com", DryRun: true}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	out := captureStdout(t, func() {
+		cmd := &SlidesReplaceTextCmd{
+			PresentationID: "pres1",
+			Find:           "needle",
+			Replacement:    "thread",
+			MatchCase:      true,
+			Pages:          []string{"p1"},
+		}
+		if err := cmd.Run(ctx, flags); err != nil {
+			t.Fatalf("Run: %v", err)
+		}
+	})
+
+	var body slides.BatchUpdatePresentationRequest
+	if err := json.Unmarshal([]byte(out), &body); err != nil {
+		t.Fatalf("dry-run output should be valid JSON: %v\nout=%s", err, out)
+	}
+	if len(body.Requests) != 1 || body.Requests[0].ReplaceAllText == nil {
+		t.Fatalf("expected single ReplaceAllText request in dry-run, got %+v", body.Requests)
+	}
+	rr := body.Requests[0].ReplaceAllText
+	if rr.ReplaceText != "thread" || rr.ContainsText.Text != "needle" || !rr.ContainsText.MatchCase {
+		t.Errorf("unexpected dry-run request body: %+v", rr)
+	}
+	if len(rr.PageObjectIds) != 1 || rr.PageObjectIds[0] != "p1" {
+		t.Errorf("expected pageObjectIds=[p1], got %+v", rr.PageObjectIds)
+	}
+}
+
+func TestSlidesReplaceText_EmptyFind(t *testing.T) {
+	origSlides := newSlidesService
+	t.Cleanup(func() { newSlidesService = origSlides })
+
+	newSlidesService = func(context.Context, string) (*slides.Service, error) {
+		t.Fatal("slides service should not be created")
+		return nil, context.Canceled
+	}
+
+	flags := &RootFlags{Account: "a@b.com"}
+	u, uiErr := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})
+	if uiErr != nil {
+		t.Fatalf("ui.New: %v", uiErr)
+	}
+	ctx := ui.WithUI(context.Background(), u)
+
+	cmd := &SlidesReplaceTextCmd{
+		PresentationID: "pres1",
+		Find:           "",
+		Replacement:    "anything",
+	}
+	err := cmd.Run(ctx, flags)
+	if err == nil || !strings.Contains(err.Error(), "empty find") {
+		t.Fatalf("expected empty find error, got: %v", err)
+	}
+}