diff --git a/src/components/code-diff/code-diff.scss b/src/components/code-diff/code-diff.scss
index 36843d886e..393192f862 100644
--- a/src/components/code-diff/code-diff.scss
+++ b/src/components/code-diff/code-diff.scss
@@ -110,6 +110,42 @@
     display: flex;
     align-items: center;
     gap: 0.25rem;
+    // Pushes the toolbar to the right edge regardless of whether the labels
+    // block is rendered (it isn't in split mode).
+    margin-left: auto;
+}
+
+// ─── Split-mode column labels ────────────────────────────────────────
+// Renders below the actions toolbar, mirroring the 4-cell layout of
+// `.diff-line--split` so the `oldHeading` / `newHeading` text sits
+// directly above the columns they describe.
+.diff-header__column-labels {
+    display: flex;
+    align-items: stretch;
+    border-bottom: 1px solid var(--diff-border-color);
+    @include mixins.font-family(sans-serif);
+    font-size: 0.875rem;
+}
+
+.diff-header__column-gutter {
+    width: var(--limel-line-number-min-width);
+    flex-shrink: 0;
+    background: var(--diff-gutter-bg);
+}
+
+.diff-header__column-label {
+    flex: 1;
+    min-width: 0;
+    padding: 0.375rem 0.75rem;
+    font-weight: 500;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+
+    &--old {
+        // Divider matches the split divider between the diff columns below.
+        border-right: 1px solid var(--diff-split-divider-color);
+    }
 }
 
 .search-toggle--active {
@@ -158,6 +194,10 @@
         flex-grow: 1;
     }
 
+    limel-button-group {
+        flex-shrink: 0;
+    }
+
     &__count {
         color: var(--diff-collapsed-text-color);
         white-space: nowrap;
diff --git a/src/components/code-diff/code-diff.tsx b/src/components/code-diff/code-diff.tsx
index e32de84496..233fa811b3 100644
--- a/src/components/code-diff/code-diff.tsx
+++ b/src/components/code-diff/code-diff.tsx
@@ -10,9 +10,16 @@ import {
     SplitDiffLine,
 } from './types';
 import { ActionBarItem } from '../action-bar/action-bar.types';
+import { Button } from '../button/button.types';
 import { buildSplitLines, computeDiff, normalizeForDiff } from './diff-engine';
 import { tokenize, SyntaxToken } from './syntax-highlighter';
-import { buildSearchRegex, navigateMatchIndex } from './search-utils';
+import {
+    buildSearchRegex,
+    navigateMatchIndex,
+    pickDefaultScope,
+    lineMatchesScope,
+    SearchScope,
+} from './search-utils';
 import {
     extractRemovedContent,
     extractRemovedContentFromSplit,
@@ -140,12 +147,15 @@ export class CodeDiff {
     @State()
     private currentMatchIndex: number = 0;
 
+    @State()
+    private searchScope: SearchScope = 'removed';
+
     private focusedRowIndex: number = -1;
     private normalizedOldText: string = '';
 
     /**
      * Render-time counter that increments for each search match
-     * found while rendering removed lines. Used to determine which
+     * found while rendering in-scope lines. Used to determine which
      * match is the "current" one for navigation highlighting.
      */
     private searchMatchCounter: number = 0;
@@ -156,10 +166,11 @@ export class CodeDiff {
     private totalSearchMatches: number = 0;
 
     /**
-     * Whether the current render is inside a removed line,
-     * so search highlighting knows when to activate.
+     * Whether the current line being rendered participates in the
+     * active search scope, so search highlighting knows when to
+     * activate.
      */
-    private isRenderingRemovedLine: boolean = false;
+    private isRenderingSearchableLine: boolean = false;
 
     /**
      * Cached search regex for the current render pass.
@@ -359,13 +370,16 @@ export class CodeDiff {
 
         const { additions, deletions } = this.diffResult;
         const hasDiff = additions > 0 || deletions > 0;
+        const isSplit = this.layout === 'split';
 
-        return (
+        return [
             <div class="diff-header">
-                <div class="diff-header__labels">
-                    <span class="diff-header__old">{oldHeading}</span>
-                    <span class="diff-header__new">{newHeading}</span>
-                </div>
+                {!isSplit && (
+                    <div class="diff-header__labels">
+                        <span class="diff-header__old">{oldHeading}</span>
+                        <span class="diff-header__new">{newHeading}</span>
+                    </div>
+                )}
                 <div class="diff-header__actions">
                     <div class="diff-header__stats">
                         {additions > 0 && (
@@ -376,10 +390,25 @@ export class CodeDiff {
                         )}
                     </div>
                     {hasDiff && this.renderCopyButton()}
-                    {deletions > 0 && this.renderSearchToggle()}
+                    {hasDiff && this.renderSearchToggle()}
                 </div>
-            </div>
-        );
+            </div>,
+            isSplit && (
+                // In split mode the labels live in their own row below the
+                // actions toolbar, mirroring the 4-cell layout of `.diff-line--split`
+                // so each label sits above the column it describes.
+                <div class="diff-header__column-labels" role="row">
+                    <span class="diff-header__column-gutter" />
+                    <span class="diff-header__column-label diff-header__column-label--old">
+                        {oldHeading}
+                    </span>
+                    <span class="diff-header__column-gutter" />
+                    <span class="diff-header__column-label diff-header__column-label--new">
+                        {newHeading}
+                    </span>
+                </div>
+            ),
+        ];
     }
 
     private renderCopyButton() {
@@ -437,6 +466,14 @@ export class CodeDiff {
 
         return (
             <div class="search-bar">
+                <limel-button-group
+                    class="search-bar__scope"
+                    aria-label={this.getTranslation('code-diff.search-scope')}
+                    value={this.getScopeButtons()}
+                    onChange={(e: CustomEvent<Button>) =>
+                        this.onScopeChange(e.detail)
+                    }
+                />
                 <limel-input-field
                     class="search-bar__input"
                     type="search"
@@ -457,9 +494,12 @@ export class CodeDiff {
 
     private toggleSearch() {
         this.searchVisible = !this.searchVisible;
-        if (!this.searchVisible) {
+        if (this.searchVisible) {
+            this.searchScope = pickDefaultScope(this.diffResult);
+        } else {
             this.searchTerm = '';
             this.currentMatchIndex = 0;
+            this.searchScope = 'removed';
         }
     }
 
@@ -515,6 +555,37 @@ export class CodeDiff {
         ];
     }
 
+    private getScopeButtons(): Button[] {
+        return [
+            {
+                id: 'removed',
+                title: this.getTranslation('code-diff.search-scope-removed'),
+                icon: 'minus',
+                selected: this.searchScope === 'removed',
+            },
+            {
+                id: 'added',
+                title: this.getTranslation('code-diff.search-scope-added'),
+                icon: 'plus_math',
+                selected: this.searchScope === 'added',
+            },
+            {
+                id: 'changed',
+                title: this.getTranslation('code-diff.search-scope-changed'),
+                icon: 'compare_arrows',
+                selected: this.searchScope === 'changed',
+            },
+        ];
+    }
+
+    private onScopeChange(button: Button) {
+        const id = button.id;
+        if (id === 'removed' || id === 'added' || id === 'changed') {
+            this.searchScope = id;
+            this.currentMatchIndex = 0;
+        }
+    }
+
     private onSearchAction(event: CustomEvent<ActionBarItem>) {
         const { value } = event.detail;
         if (value === 'prev') {
@@ -769,8 +840,9 @@ export class CodeDiff {
     }
 
     private renderContent(line: DiffLine) {
-        this.isRenderingRemovedLine =
-            line.type === 'removed' && this.searchTerm.length > 0;
+        this.isRenderingSearchableLine =
+            this.searchTerm.length > 0 &&
+            lineMatchesScope(line.type, this.searchScope);
 
         if (!line.segments || line.segments.length === 0) {
             return this.renderSyntaxTokens(line.content);
@@ -815,7 +887,7 @@ export class CodeDiff {
     }
 
     private renderSearchableText(text: string): any {
-        if (!this.isRenderingRemovedLine || !this.activeSearchRegex) {
+        if (!this.isRenderingSearchableLine || !this.activeSearchRegex) {
             return text;
         }
 
diff --git a/src/components/code-diff/search-utils.spec.ts b/src/components/code-diff/search-utils.spec.ts
index fcc63c9a80..1fa5f881ee 100644
--- a/src/components/code-diff/search-utils.spec.ts
+++ b/src/components/code-diff/search-utils.spec.ts
@@ -3,6 +3,8 @@ import {
     escapeRegex,
     buildSearchRegex,
     navigateMatchIndex,
+    pickDefaultScope,
+    lineMatchesScope,
 } from './search-utils';
 
 describe('escapeRegex', () => {
@@ -66,3 +68,65 @@ describe('navigateMatchIndex', () => {
         expect(navigateMatchIndex(0, -1, 5)).toBe(4);
     });
 });
+
+describe('pickDefaultScope', () => {
+    it('returns "removed" when there are deletions', () => {
+        expect(pickDefaultScope({ additions: 0, deletions: 3 })).toBe(
+            'removed'
+        );
+    });
+
+    it('returns "removed" when both additions and deletions exist', () => {
+        expect(pickDefaultScope({ additions: 5, deletions: 2 })).toBe(
+            'removed'
+        );
+    });
+
+    it('returns "added" when only additions exist', () => {
+        expect(pickDefaultScope({ additions: 4, deletions: 0 })).toBe('added');
+    });
+});
+
+describe('lineMatchesScope', () => {
+    describe('scope: removed', () => {
+        it('matches removed lines', () => {
+            expect(lineMatchesScope('removed', 'removed')).toBe(true);
+        });
+
+        it('does not match added lines', () => {
+            expect(lineMatchesScope('added', 'removed')).toBe(false);
+        });
+
+        it('does not match context lines', () => {
+            expect(lineMatchesScope('context', 'removed')).toBe(false);
+        });
+    });
+
+    describe('scope: added', () => {
+        it('matches added lines', () => {
+            expect(lineMatchesScope('added', 'added')).toBe(true);
+        });
+
+        it('does not match removed lines', () => {
+            expect(lineMatchesScope('removed', 'added')).toBe(false);
+        });
+
+        it('does not match context lines', () => {
+            expect(lineMatchesScope('context', 'added')).toBe(false);
+        });
+    });
+
+    describe('scope: changed', () => {
+        it('matches removed lines', () => {
+            expect(lineMatchesScope('removed', 'changed')).toBe(true);
+        });
+
+        it('matches added lines', () => {
+            expect(lineMatchesScope('added', 'changed')).toBe(true);
+        });
+
+        it('does not match context lines', () => {
+            expect(lineMatchesScope('context', 'changed')).toBe(false);
+        });
+    });
+});
diff --git a/src/components/code-diff/search-utils.ts b/src/components/code-diff/search-utils.ts
index 129f6e5e35..8c9f466950 100644
--- a/src/components/code-diff/search-utils.ts
+++ b/src/components/code-diff/search-utils.ts
@@ -2,6 +2,13 @@
  * Pure utility functions for search-within-diff functionality.
  */
 
+import type { DiffLine } from './types';
+
+/**
+ * The line types that the in-diff search operates on.
+ */
+export type SearchScope = 'removed' | 'added' | 'changed';
+
 /**
  * Escape special regex characters in a search term so it can
  * be used as a literal pattern in a RegExp constructor.
@@ -48,3 +55,47 @@ export function navigateMatchIndex(
 
     return (currentIndex + direction + total) % total;
 }
+
+/**
+ * Pick the default `SearchScope` to use when the search panel opens.
+ * Falls back to `'added'` when there are no removed lines, so the
+ * panel never opens with a scope that has zero matches.
+ *
+ * @param stats - the current diff statistics
+ * @param stats.additions - number of added lines in the diff
+ * @param stats.deletions - number of removed lines in the diff
+ * @returns the scope that should be active when the panel opens
+ */
+export function pickDefaultScope(stats: {
+    additions: number;
+    deletions: number;
+}): SearchScope {
+    if (stats.deletions > 0) {
+        return 'removed';
+    }
+
+    return 'added';
+}
+
+/**
+ * Whether a line of the given type participates in the active
+ * `SearchScope`. Context lines are never included.
+ *
+ * @param lineType - the type of the diff line being considered
+ * @param scope - the active search scope
+ * @returns true when the line participates in the scope, false otherwise
+ */
+export function lineMatchesScope(
+    lineType: DiffLine['type'],
+    scope: SearchScope
+): boolean {
+    if (lineType === 'context') {
+        return false;
+    }
+
+    if (scope === 'changed') {
+        return true;
+    }
+
+    return lineType === scope;
+}
diff --git a/src/translations/da.ts b/src/translations/da.ts
index 44985d86ce..124c5f4e03 100644
--- a/src/translations/da.ts
+++ b/src/translations/da.ts
@@ -87,7 +87,11 @@ Du kan fortsætte med at blokere billeder (e-mailen kan se ufuldstændig ud) ell
     'code-diff.copied': 'Kopieret!',
     'code-diff.copied-to-clipboard': 'Kopieret til udklipsholder',
     'code-diff.copy-change': 'Kopiér gammel version af denne ændring',
-    'code-diff.search': 'Søg i fjernede linjer',
+    'code-diff.search': 'Søg',
+    'code-diff.search-scope': 'Søgeområde',
+    'code-diff.search-scope-removed': 'Fjernede linjer',
+    'code-diff.search-scope-added': 'Tilføjede linjer',
+    'code-diff.search-scope-changed': 'Ændrede linjer',
     'code-diff.previous-match': 'Forrige match',
     'code-diff.next-match': 'Næste match',
     'code-diff.close-search': 'Luk søgning',
diff --git a/src/translations/de.ts b/src/translations/de.ts
index 4a903cb21f..87377095da 100644
--- a/src/translations/de.ts
+++ b/src/translations/de.ts
@@ -88,7 +88,11 @@ Sie können Bilder weiterhin blockieren (die E-Mail kann unvollständig aussehen
     'code-diff.copied': 'Kopiert!',
     'code-diff.copied-to-clipboard': 'In die Zwischenablage kopiert',
     'code-diff.copy-change': 'Alte Version dieser Änderung kopieren',
-    'code-diff.search': 'Entfernte Zeilen durchsuchen',
+    'code-diff.search': 'Suchen',
+    'code-diff.search-scope': 'Suchbereich',
+    'code-diff.search-scope-removed': 'Entfernte Zeilen',
+    'code-diff.search-scope-added': 'Hinzugefügte Zeilen',
+    'code-diff.search-scope-changed': 'Geänderte Zeilen',
     'code-diff.previous-match': 'Vorherige Übereinstimmung',
     'code-diff.next-match': 'Nächste Übereinstimmung',
     'code-diff.close-search': 'Suche schließen',
diff --git a/src/translations/en.ts b/src/translations/en.ts
index ffdee04af6..9b96c8e132 100644
--- a/src/translations/en.ts
+++ b/src/translations/en.ts
@@ -86,7 +86,11 @@ You can keep images blocked (the email may look incomplete), or load them if you
     'code-diff.copied': 'Copied!',
     'code-diff.copied-to-clipboard': 'Copied to clipboard',
     'code-diff.copy-change': 'Copy old version of this change',
-    'code-diff.search': 'Search removed lines',
+    'code-diff.search': 'Search',
+    'code-diff.search-scope': 'Search scope',
+    'code-diff.search-scope-removed': 'Removed lines',
+    'code-diff.search-scope-added': 'Added lines',
+    'code-diff.search-scope-changed': 'Changed lines',
     'code-diff.previous-match': 'Previous match',
     'code-diff.next-match': 'Next match',
     'code-diff.close-search': 'Close search',
diff --git a/src/translations/fi.ts b/src/translations/fi.ts
index 3c95a2d4fc..412bb05b6a 100644
--- a/src/translations/fi.ts
+++ b/src/translations/fi.ts
@@ -87,7 +87,11 @@ Voit pitää kuvat estettyinä (sähköposti voi näyttää puutteelliselta) tai
     'code-diff.copied': 'Kopioitu!',
     'code-diff.copied-to-clipboard': 'Kopioitu leikepöydälle',
     'code-diff.copy-change': 'Kopioi tämän muutoksen vanha versio',
-    'code-diff.search': 'Hae poistetuista riveistä',
+    'code-diff.search': 'Hae',
+    'code-diff.search-scope': 'Hakualue',
+    'code-diff.search-scope-removed': 'Poistetut rivit',
+    'code-diff.search-scope-added': 'Lisätyt rivit',
+    'code-diff.search-scope-changed': 'Muuttuneet rivit',
     'code-diff.previous-match': 'Edellinen osuma',
     'code-diff.next-match': 'Seuraava osuma',
     'code-diff.close-search': 'Sulje haku',
diff --git a/src/translations/fr.ts b/src/translations/fr.ts
index a32caa7c54..c91753e84c 100644
--- a/src/translations/fr.ts
+++ b/src/translations/fr.ts
@@ -90,7 +90,11 @@ Vous pouvez laisser les images bloquées (l'e-mail peut sembler incomplet) ou le
     'code-diff.copied-to-clipboard': 'Copié dans le presse-papiers',
     'code-diff.copy-change':
         'Copier l\u2019ancienne version de cette modification',
-    'code-diff.search': 'Rechercher dans les lignes supprimées',
+    'code-diff.search': 'Rechercher',
+    'code-diff.search-scope': 'Portée de la recherche',
+    'code-diff.search-scope-removed': 'Lignes supprimées',
+    'code-diff.search-scope-added': 'Lignes ajoutées',
+    'code-diff.search-scope-changed': 'Lignes modifiées',
     'code-diff.previous-match': 'Correspondance précédente',
     'code-diff.next-match': 'Correspondance suivante',
     'code-diff.close-search': 'Fermer la recherche',
diff --git a/src/translations/nl.ts b/src/translations/nl.ts
index e09e8a7546..25a23636fe 100644
--- a/src/translations/nl.ts
+++ b/src/translations/nl.ts
@@ -87,7 +87,11 @@ Je kunt afbeeldingen geblokkeerd houden (de e-mail kan er onvolledig uitzien) of
     'code-diff.copied': 'Gekopieerd!',
     'code-diff.copied-to-clipboard': 'Gekopieerd naar klembord',
     'code-diff.copy-change': 'Oude versie van deze wijziging kopiëren',
-    'code-diff.search': 'Zoeken in verwijderde regels',
+    'code-diff.search': 'Zoeken',
+    'code-diff.search-scope': 'Zoekbereik',
+    'code-diff.search-scope-removed': 'Verwijderde regels',
+    'code-diff.search-scope-added': 'Toegevoegde regels',
+    'code-diff.search-scope-changed': 'Gewijzigde regels',
     'code-diff.previous-match': 'Vorige overeenkomst',
     'code-diff.next-match': 'Volgende overeenkomst',
     'code-diff.close-search': 'Zoeken sluiten',
diff --git a/src/translations/no.ts b/src/translations/no.ts
index 6f328a4f30..ed79c0dfb2 100644
--- a/src/translations/no.ts
+++ b/src/translations/no.ts
@@ -87,7 +87,11 @@ Du kan fortsette å blokkere bilder (e-posten kan se ufullstendig ut), eller las
     'code-diff.copied': 'Kopiert!',
     'code-diff.copied-to-clipboard': 'Kopiert til utklippstavlen',
     'code-diff.copy-change': 'Kopier gammel versjon av denne endringen',
-    'code-diff.search': 'Søk i fjernede linjer',
+    'code-diff.search': 'Søk',
+    'code-diff.search-scope': 'Søkeområde',
+    'code-diff.search-scope-removed': 'Fjernede linjer',
+    'code-diff.search-scope-added': 'Tillagte linjer',
+    'code-diff.search-scope-changed': 'Endrede linjer',
     'code-diff.previous-match': 'Forrige treff',
     'code-diff.next-match': 'Neste treff',
     'code-diff.close-search': 'Lukk søk',
diff --git a/src/translations/sv.ts b/src/translations/sv.ts
index 96fce8337e..6ca7b8975e 100644
--- a/src/translations/sv.ts
+++ b/src/translations/sv.ts
@@ -87,7 +87,11 @@ Du kan fortsätta blockera bilder (e-posten kan se ofullständig ut) eller ladda
     'code-diff.copied': 'Kopierat!',
     'code-diff.copied-to-clipboard': 'Kopierat till urklipp',
     'code-diff.copy-change': 'Kopiera den gamla versionen av ändringen',
-    'code-diff.search': 'Sök i borttagna rader',
+    'code-diff.search': 'Sök',
+    'code-diff.search-scope': 'Sökområde',
+    'code-diff.search-scope-removed': 'Borttagna rader',
+    'code-diff.search-scope-added': 'Tillagda rader',
+    'code-diff.search-scope-changed': 'Ändrade rader',
     'code-diff.previous-match': 'Föregående träff',
     'code-diff.next-match': 'Nästa träff',
     'code-diff.close-search': 'Stäng sökning',