diff --git a/.taskfiles/frontend.yml b/.taskfiles/frontend.yml
index 4f87226f93..b402df7d1b 100644
--- a/.taskfiles/frontend.yml
+++ b/.taskfiles/frontend.yml
@@ -80,6 +80,12 @@ tasks:
       OPEN: '{{.OPEN | default ""}}'
     env:
       BACKEND_URL: '{{.BACKEND_URL}}'
+      # Dev-only browser-tab label so concurrent worktrees are distinguishable.
+      # Only the worktree folder basename (e.g. "wt1") is exposed — never the
+      # full path, hostname, or user. Consumed at dev-serve time by vite.config
+      # and dropped from production builds.
+      STIRLING_DEV_LABEL:
+        sh: basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)"
     cmds:
       - npx vite editor --mode {{.MODE}} --port {{.PORT}}{{if .OPEN}} --open{{end}}
 
diff --git a/frontend/editor/src/core/components/tools/ToolPicker.tsx b/frontend/editor/src/core/components/tools/ToolPicker.tsx
index 27b0caf7d5..779e945b8c 100644
--- a/frontend/editor/src/core/components/tools/ToolPicker.tsx
+++ b/frontend/editor/src/core/components/tools/ToolPicker.tsx
@@ -197,7 +197,7 @@ const ToolPicker = ({
         ) : (
           <>
             {/* All-tools view: favourites + recommended + all subcategories. */}
-            <Stack p="sm" gap="xs">
+            <Stack px="sm" pb="sm" pt={4} gap="xs">
               {favoriteToolItems.length > 0 && (
                 <Box w="100%">
                   <div style={HEADER_TEXT_STYLE}>
diff --git a/frontend/editor/src/core/utils/applyDevWorktreeLabel.ts b/frontend/editor/src/core/utils/applyDevWorktreeLabel.ts
new file mode 100644
index 0000000000..f1c0164e27
--- /dev/null
+++ b/frontend/editor/src/core/utils/applyDevWorktreeLabel.ts
@@ -0,0 +1,39 @@
+/**
+ * Prefixes the browser tab title with the current worktree name during local
+ * development so multiple concurrently-running worktrees (e.g. wt1, wt2, spdf1)
+ * are distinguishable at a glance instead of all showing "Stirling PDF".
+ *
+ * The label is injected as a build-time constant by vite.config, sourced from
+ * the top-level dev tasks. It is an empty string in production builds, so this
+ * whole feature compiles away to a no-op outside `vite` dev-serve.
+ */
+
+const LABEL =
+  typeof __DEV_WORKTREE_LABEL__ === "string" ? __DEV_WORKTREE_LABEL__ : "";
+
+export function applyDevWorktreeLabel(): void {
+  if (!LABEL || typeof document === "undefined") {
+    return;
+  }
+
+  const prefix = `[${LABEL}] `;
+
+  const ensurePrefixed = () => {
+    if (!document.title.startsWith(prefix)) {
+      // The app rewrites document.title on route/tool changes; re-apply the
+      // prefix on top of whatever the app just set.
+      document.title = prefix + document.title;
+    }
+  };
+
+  ensurePrefixed();
+
+  const titleEl = document.querySelector("title");
+  if (titleEl) {
+    new MutationObserver(ensurePrefixed).observe(titleEl, {
+      childList: true,
+      characterData: true,
+      subtree: true,
+    });
+  }
+}
diff --git a/frontend/editor/src/index.tsx b/frontend/editor/src/index.tsx
index d776918bd1..6ee0f6df51 100644
--- a/frontend/editor/src/index.tsx
+++ b/frontend/editor/src/index.tsx
@@ -14,9 +14,12 @@ import { BrowserRouter } from "react-router-dom";
 import App from "@app/App";
 import "@app/i18n"; // Initialize i18next
 import { BASE_PATH } from "@app/constants/app";
+import { applyDevWorktreeLabel } from "@app/utils/applyDevWorktreeLabel";
 
 import { startEagerWasmCompilation } from "@app/services/wasmPrecompiler";
 
+applyDevWorktreeLabel();
+
 if (typeof window !== "undefined") {
   const scheduleCompilation = () => {
     if (typeof requestIdleCallback === "function") {
diff --git a/frontend/editor/vite-env.d.ts b/frontend/editor/vite-env.d.ts
index e9fb24e496..a410ba3bc7 100644
--- a/frontend/editor/vite-env.d.ts
+++ b/frontend/editor/vite-env.d.ts
@@ -32,3 +32,10 @@ interface ImportMetaEnv {
 interface ImportMeta {
   readonly env: ImportMetaEnv;
 }
+
+/**
+ * Dev-only worktree folder basename injected by vite.config at dev-serve time
+ * (empty string in production builds). Used to prefix the browser tab title so
+ * concurrent worktrees are distinguishable.
+ */
+declare const __DEV_WORKTREE_LABEL__: string;
diff --git a/frontend/editor/vite.config.ts b/frontend/editor/vite.config.ts
index 059f98332e..b5733bfe02 100644
--- a/frontend/editor/vite.config.ts
+++ b/frontend/editor/vite.config.ts
@@ -182,7 +182,13 @@ const TSCONFIG_MAP: Record<BuildMode, string> = {
   prototypes: "./tsconfig.prototypes.vite.json",
 };
 
-export default defineConfig(async ({ mode }) => {
+export default defineConfig(async ({ mode, command }) => {
+  // Dev-only browser-tab label (worktree folder basename) surfaced by the
+  // top-level dev tasks so concurrent worktrees have distinguishable tabs.
+  // Only injected during `vite` (dev serve) — never baked into a production
+  // build — and carries only the folder name, no path/host/user info.
+  const devWorktreeLabel =
+    command === "serve" ? (process.env.STIRLING_DEV_LABEL ?? "") : "";
   // Load env files relative to this config (frontend/editor/), regardless of
   // where the build was invoked from. The previous `process.cwd()` worked when
   // this file lived at frontend/, but after the editor was moved under
@@ -250,6 +256,9 @@ export default defineConfig(async ({ mode }) => {
         };
 
   return {
+    define: {
+      __DEV_WORKTREE_LABEL__: JSON.stringify(devWorktreeLabel),
+    },
     plugins: [
       react(),
       ...(runSubpath ? [subpathBareRedirectPlugin(runSubpath)] : []),