diff --git a/packages/desktop/assets/icon-dev.png b/packages/desktop/assets/icon-dev.png
new file mode 100644
index 000000000..00ba1cc22
Binary files /dev/null and b/packages/desktop/assets/icon-dev.png differ
diff --git a/packages/desktop/scripts/dev-runner-config.mjs b/packages/desktop/scripts/dev-runner-config.mjs
index c855b3e5d..706728414 100644
--- a/packages/desktop/scripts/dev-runner-config.mjs
+++ b/packages/desktop/scripts/dev-runner-config.mjs
@@ -1,4 +1,4 @@
-export function createElectronSpawnOptions({ env, colorEnv, expoDevUrl }) {
+export function createElectronSpawnOptions({ env, colorEnv, expoDevUrl, devBuildLabel }) {
   return {
     // Electron must stay in the runner's process group. Paseo workspace scripts
     // own the terminal process group, so detaching Electron lets it survive a
@@ -8,6 +8,7 @@ export function createElectronSpawnOptions({ env, colorEnv, expoDevUrl }) {
       ...env,
       ...colorEnv,
       EXPO_DEV_URL: expoDevUrl,
+      ...(devBuildLabel ? { EXPO_PUBLIC_PASEO_DEV_BUILD_LABEL: devBuildLabel } : {}),
     },
   };
 }
diff --git a/packages/desktop/scripts/dev-runner.mjs b/packages/desktop/scripts/dev-runner.mjs
index 5e0344c0d..852bf7d85 100644
--- a/packages/desktop/scripts/dev-runner.mjs
+++ b/packages/desktop/scripts/dev-runner.mjs
@@ -195,6 +195,7 @@ if (!stopping) {
       env: process.env,
       colorEnv,
       expoDevUrl,
+      devBuildLabel,
     }),
   );
 }
diff --git a/packages/desktop/src/features/stamped-icon.test.ts b/packages/desktop/src/features/stamped-icon.test.ts
new file mode 100644
index 000000000..a6e7bc578
--- /dev/null
+++ b/packages/desktop/src/features/stamped-icon.test.ts
@@ -0,0 +1,110 @@
+import { describe, expect, it } from "vitest";
+import {
+  buildImageMagickArgs,
+  computeStampGeometry,
+  resolveAppIconPath,
+  resolveMonospaceFont,
+} from "./stamped-icon";
+
+describe("stamped-icon", () => {
+  describe("resolveMonospaceFont", () => {
+    it("selects Menlo-Bold on macOS when present", () => {
+      const mockList = `
+        Font: Helvetica-Bold
+        Font: Menlo-Bold
+        Font: Courier-New-Bold
+      `;
+      expect(resolveMonospaceFont(mockList)).toBe("Menlo-Bold");
+    });
+
+    it("selects Consolas-Bold on Windows when Menlo is absent", () => {
+      const mockList = `
+        Font: Arial
+        Font: Consolas-Bold
+        Font: Courier-New
+      `;
+      expect(resolveMonospaceFont(mockList)).toBe("Consolas-Bold");
+    });
+
+    it("selects DejaVu-Sans-Mono-Bold on Linux", () => {
+      const mockList = `
+        Font: DejaVu-Sans-Mono-Bold
+        Font: FreeMono
+      `;
+      expect(resolveMonospaceFont(mockList)).toBe("DejaVu-Sans-Mono-Bold");
+    });
+
+    it("falls back to Courier when no preferred font matches", () => {
+      const mockList = `
+        Font: SomeUnknownFont
+      `;
+      expect(resolveMonospaceFont(mockList)).toBe("Courier");
+    });
+  });
+
+  describe("computeStampGeometry", () => {
+    it("computes lowercase geometry for short label", () => {
+      const geo = computeStampGeometry(512, 512, "DEV");
+      expect(geo.label).toBe("dev");
+      expect(geo.pointsize).toBeGreaterThan(0);
+      expect(geo.x1).toBeGreaterThan(0);
+      expect(geo.x2).toBeLessThan(512);
+      expect(geo.y1).toBeGreaterThan(0);
+      expect(geo.y2).toBeLessThan(512);
+    });
+
+    it("scales geometry for large images", () => {
+      const geo512 = computeStampGeometry(512, 512, "fix/desktop-stamp");
+      const geo1024 = computeStampGeometry(1024, 1024, "fix/desktop-stamp");
+
+      expect(geo1024.pointsize).toBeGreaterThan(geo512.pointsize);
+      expect(geo1024.r).toBeGreaterThan(geo512.r);
+    });
+  });
+
+  describe("buildImageMagickArgs", () => {
+    it("builds valid composite args", () => {
+      const geo = computeStampGeometry(512, 512, "test-branch");
+      const args = buildImageMagickArgs("/in.png", "/out.png", geo, "Menlo-Bold", 512, 512);
+
+      expect(args[0]).toBe("/in.png");
+      expect(args[args.length - 1]).toBe("/out.png");
+      expect(args).toContain("Menlo-Bold");
+      expect(args).toContain("test-branch");
+      expect(args).toContain("DstIn");
+      expect(args).toContain("Over");
+    });
+  });
+
+  describe("resolveAppIconPath", () => {
+    it("returns base icon path immediately when packaged", async () => {
+      const result = await resolveAppIconPath({
+        isPackaged: true,
+        baseIconPath: "/path/to/icon.png",
+        devLabel: "feature/foo",
+        cacheDir: "/cache",
+      });
+      expect(result).toBe("/path/to/icon.png");
+    });
+
+    it("returns base icon path when no dev label is provided", async () => {
+      const result = await resolveAppIconPath({
+        isPackaged: false,
+        baseIconPath: "/path/to/icon.png",
+        devLabel: null,
+        cacheDir: "/cache",
+      });
+      expect(result).toBe("/path/to/icon.png");
+    });
+
+    it("returns null if baseIconPath is null", async () => {
+      const result = await resolveAppIconPath({
+        isPackaged: false,
+        baseIconPath: null,
+        devLabel: "dev",
+        cacheDir: "/cache",
+      });
+      expect(result).toBeNull();
+    });
+  });
+});
diff --git a/packages/desktop/src/features/stamped-icon.ts b/packages/desktop/src/features/stamped-icon.ts
new file mode 100644
index 000000000..86a67a249
--- /dev/null
+++ b/packages/desktop/src/features/stamped-icon.ts
@@ -0,0 +1,259 @@
+import { execFile } from "node:child_process";
+import { existsSync, promises as fs } from "node:fs";
+import path from "node:path";
+import { promisify } from "node:util";
+
+const execFileAsync = promisify(execFile);
+const STAMP_CACHE_VERSION = "v2";
+
+export const MONOSPACE_FONT_CANDIDATES = [
+  "Menlo-Bold",
+  "SFMono-Bold",
+  "Consolas-Bold",
+  "DejaVu-Sans-Mono-Bold",
+  "Liberation-Mono-Bold",
+  "Courier-New-Bold",
+  "Courier-Bold",
+  "Courier",
+] as const;
+
+export interface StampGeometry {
+  label: string;
+  x1: number;
+  y1: number;
+  x2: number;
+  y2: number;
+  r: number;
+  pointsize: number;
+  offsetY: number;
+}
+
+export function resolveMonospaceFont(fontsListOutput: string): string {
+  for (const candidate of MONOSPACE_FONT_CANDIDATES) {
+    const regex = new RegExp(`^\\s*Font:\\s*${candidate}\\b`, "im");
+    if (regex.test(fontsListOutput)) {
+      return candidate;
+    }
+  }
+  return "Courier";
+}
+
+export function computeStampGeometry(
+  width: number,
+  height: number,
+  rawLabel: string,
+): StampGeometry {
+  const label = rawLabel.trim().toLowerCase();
+  const ph = Math.max(24, Math.round(height * 0.1));
+  const maxPointSize = Math.round(ph * 1.03);
+  const minPointSize = 12;
+  const pointsize = Math.max(
+    minPointSize,
+    Math.min(maxPointSize, Math.round((width * 0.8) / Math.max(1, label.length * 0.6))),
+  );
+  const textWidth = label.length * (pointsize * 0.6);
+  const paddingX = Math.round(ph * 0.7);
+  const pw = Math.min(
+    Math.round(width * 0.88),
+    Math.max(Math.round(width * 0.35), Math.round(textWidth + paddingX * 2)),
+  );
+  const centerY = Math.round(height * 0.81);
+  const y1 = Math.round(centerY - ph / 2);
+  const y2 = Math.round(centerY + ph / 2);
+  const x1 = Math.round((width - pw) / 2);
+  const x2 = Math.round((width + pw) / 2);
+  const r = Math.round(ph / 2);
+  const offsetY = Math.round(centerY - height / 2);
+
+  return {
+    label,
+    x1,
+    y1,
+    x2,
+    y2,
+    r,
+    pointsize,
+    offsetY,
+  };
+}
+
+export function buildImageMagickArgs(
+  inputPath: string,
+  outputPath: string,
+  geometry: StampGeometry,
+  font: string,
+  width: number,
+  height: number,
+): string[] {
+  return [
+    inputPath,
+    "(",
+    "-clone",
+    "0",
+    "-alpha",
+    "extract",
+    ")",
+    "(",
+    "-size",
+    `${width}x${height}`,
+    "xc:none",
+    "-fill",
+    "rgba(10,12,18,0.88)",
+    "-draw",
+    `roundrectangle ${geometry.x1},${geometry.y1} ${geometry.x2},${geometry.y2} ${geometry.r},${geometry.r}`,
+    "-gravity",
+    "center",
+    "-font",
+    font,
+    "-pointsize",
+    String(geometry.pointsize),
+    "-fill",
+    "#f0f0f5",
+    "-annotate",
+    `+0+${geometry.offsetY}`,
+    geometry.label,
+    ")",
+    "(",
+    "-clone",
+    "2",
+    "-clone",
+    "1",
+    "-compose",
+    "DstIn",
+    "-composite",
+    ")",
+    "-delete",
+    "1,2",
+    "-compose",
+    "Over",
+    "-composite",
+    outputPath,
+  ];
+}
+
+let cachedMonospaceFont: string | null = null;
+
+async function detectMonospaceFont(magickBin: string): Promise<string> {
+  if (cachedMonospaceFont) {
+    return cachedMonospaceFont;
+  }
+  try {
+    const { stdout } = await execFileAsync(magickBin, ["-list", "font"], {
+      encoding: "utf-8",
+      timeout: 3000,
+      windowsHide: true,
+    });
+    cachedMonospaceFont = resolveMonospaceFont(stdout);
+  } catch {
+    cachedMonospaceFont = "Courier";
+  }
+  return cachedMonospaceFont;
+}
+
+function sanitizeLabelForFilename(label: string): string {
+  return label
+    .trim()
+    .toLowerCase()
+    .replace(/[^a-z0-9._-]+/g, "-")
+    .replace(/^-+|-+$/g, "")
+    .slice(0, 60);
+}
+
+async function getImageDimensions(
+  magickBin: string,
+  filePath: string,
+): Promise<{ width: number; height: number } | null> {
+  try {
+    const { stdout } = await execFileAsync(magickBin, ["identify", "-format", "%wx%h", filePath], {
+      encoding: "utf-8",
+      timeout: 3000,
+      windowsHide: true,
+    });
+    const match = stdout.trim().match(/^(\d+)x(\d+)$/);
+    if (match) {
+      return { width: Number.parseInt(match[1], 10), height: Number.parseInt(match[2], 10) };
+    }
+  } catch {
+    // fallback if identify fails
+  }
+  return null;
+}
+
+export async function getStampedIconPath(options: {
+  baseIconPath: string;
+  label: string;
+  cacheDir: string;
+}): Promise<string | null> {
+  const { baseIconPath, label, cacheDir } = options;
+  if (!label || !existsSync(baseIconPath)) {
+    return null;
+  }
+
+  const safeLabel = sanitizeLabelForFilename(label) || "dev";
+  const baseName = path.basename(baseIconPath, path.extname(baseIconPath));
+  const outputPath = path.join(
+    cacheDir,
+    `icon-stamp-${STAMP_CACHE_VERSION}-${baseName}-${safeLabel}.png`,
+  );
+
+  if (existsSync(outputPath)) {
+    return outputPath;
+  }
+
+  const magickBin = process.platform === "win32" ? "magick.exe" : "magick";
+  try {
+    const dimensions = (await getImageDimensions(magickBin, baseIconPath)) ?? {
+      width: 512,
+      height: 512,
+    };
+    const font = await detectMonospaceFont(magickBin);
+    const geometry = computeStampGeometry(dimensions.width, dimensions.height, label);
+
+    await fs.mkdir(cacheDir, { recursive: true });
+    const args = buildImageMagickArgs(
+      baseIconPath,
+      outputPath,
+      geometry,
+      font,
+      dimensions.width,
+      dimensions.height,
+    );
+
+    await execFileAsync(magickBin, args, {
+      timeout: 6000,
+      windowsHide: true,
+    });
+
+    if (existsSync(outputPath)) {
+      return outputPath;
+    }
+  } catch {
+    // Graceful degradation: dev icon stamping is optional and fails silently to base icon.
+  }
+
+  return null;
+}
+
+export async function resolveAppIconPath(options: {
+  isPackaged: boolean;
+  baseIconPath: string | null;
+  devLabel: string | null;
+  cacheDir: string;
+}): Promise<string | null> {
+  const { isPackaged, baseIconPath, devLabel, cacheDir } = options;
+  if (!baseIconPath) {
+    return null;
+  }
+
+  if (isPackaged || !devLabel) {
+    return baseIconPath;
+  }
+
+  const stamped = await getStampedIconPath({
+    baseIconPath,
+    label: devLabel,
+    cacheDir,
+  });
+
+  return stamped ?? baseIconPath;
+}
diff --git a/packages/desktop/src/main.ts b/packages/desktop/src/main.ts
index da3630ff4..399272402 100644
--- a/packages/desktop/src/main.ts
+++ b/packages/desktop/src/main.ts
@@ -47,6 +47,7 @@ import {
 } from "./features/notifications.js";
 import { registerOpenerHandlers } from "./features/opener.js";
 import { registerEditorTargetHandlers } from "./features/editor-targets/ipc.js";
+import { resolveAppIconPath } from "./features/stamped-icon.js";
 import { setupApplicationMenu } from "./features/menu.js";
 import {
   BROWSER_NEW_TAB_REQUEST_EVENT,
@@ -646,11 +647,15 @@ function getWindowIconCandidates(): string[] {
   }
   if (process.platform === "win32") {
     return [
+      path.resolve(__dirname, "../assets/icon-dev.png"),
       path.resolve(__dirname, "../assets/icon.ico"),
       path.resolve(__dirname, "../assets/icon.png"),
     ];
   }
-  return [path.resolve(__dirname, "../assets/icon.png")];
+  return [
+    path.resolve(__dirname, "../assets/icon-dev.png"),
+    path.resolve(__dirname, "../assets/icon.png"),
+  ];
 }
 
 function getWindowIconPath(): string | null {
@@ -658,12 +663,40 @@ function getWindowIconPath(): string | null {
   return candidates.find((candidate) => existsSync(candidate)) ?? null;
 }
 
-function applyAppIcon(): void {
+function getDevBuildLabel(): string | null {
+  if (app.isPackaged) {
+    return null;
+  }
+  return process.env.EXPO_PUBLIC_PASEO_DEV_BUILD_LABEL?.trim() || null;
+}
+
+let cachedEffectiveIconPath: string | null = null;
+
+async function getEffectiveAppIconPath(): Promise<string | null> {
+  if (cachedEffectiveIconPath !== null) {
+    return cachedEffectiveIconPath;
+  }
+  const baseIconPath = getWindowIconPath();
+  if (app.isPackaged || !baseIconPath) {
+    cachedEffectiveIconPath = baseIconPath;
+    return baseIconPath;
+  }
+  const devLabel = getDevBuildLabel();
+  cachedEffectiveIconPath = await resolveAppIconPath({
+    isPackaged: false,
+    baseIconPath,
+    devLabel,
+    cacheDir: app.getPath("userData"),
+  });
+  return cachedEffectiveIconPath;
+}
+
+async function applyAppIcon(): Promise<void> {
   if (process.platform !== "darwin") {
     return;
   }
 
-  const iconPath = getWindowIconPath();
+  const iconPath = await getEffectiveAppIconPath();
   if (!iconPath) {
     return;
   }
@@ -691,7 +724,7 @@ async function createWindow(
     restoreWindowState?: boolean;
   } = {},
 ): Promise<BrowserWindow> {
-  const iconPath = getWindowIconPath();
+  const iconPath = await getEffectiveAppIconPath();
   const systemTheme = resolveSystemWindowTheme();
 
   // Only the first window of a session restores and persists saved geometry.
@@ -972,7 +1005,7 @@ async function bootstrap(): Promise<void> {
     return net.fetch(pathToFileURL(filePath).toString());
   });
 
-  applyAppIcon();
+  await applyAppIcon();
   setupApplicationMenu({
     onNewWindow: () => {
       void createWindow().catch((error) => {