diff --git a/scripts/test-parallel.mjs b/scripts/test-parallel.mjs
index b685d41820..a4a9c3bd38 100644
--- a/scripts/test-parallel.mjs
+++ b/scripts/test-parallel.mjs
@@ -139,7 +139,8 @@ const maxWorkersForRun = (name) => {
     return 1;
   }
   if (name === "unit-isolated") {
-    return 1;
+    // Local: allow a bit of parallelism while keeping this run stable.
+    return Math.min(4, localWorkers);
   }
   if (name === "extensions") {
     return defaultExtensionsWorkers;
diff --git a/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts b/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
index 04f01014ae..2677d840eb 100644
--- a/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
+++ b/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
@@ -1,14 +1,27 @@
-import { describe, expect, it, vi } from "vitest";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterAll, beforeAll, describe, expect, it, vi } from "vitest";
 import type { BrowserServerState } from "./server-context.js";
 import { createBrowserRouteContext } from "./server-context.js";
 
+const chromeUserDataDir = vi.hoisted(() => ({ dir: "/tmp/openclaw" }));
+
+beforeAll(async () => {
+  chromeUserDataDir.dir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-chrome-user-data-"));
+});
+
+afterAll(async () => {
+  await fs.rm(chromeUserDataDir.dir, { recursive: true, force: true });
+});
+
 vi.mock("./chrome.js", () => ({
   isChromeCdpReady: vi.fn(async () => true),
   isChromeReachable: vi.fn(async () => true),
   launchOpenClawChrome: vi.fn(async () => {
     throw new Error("unexpected launch");
   }),
-  resolveOpenClawUserDataDir: vi.fn(() => "/tmp/openclaw"),
+  resolveOpenClawUserDataDir: vi.fn(() => chromeUserDataDir.dir),
   stopOpenClawChrome: vi.fn(async () => {}),
 }));
 
diff --git a/src/browser/server-context.remote-tab-ops.test.ts b/src/browser/server-context.remote-tab-ops.test.ts
index a791bd10ec..8e06b30824 100644
--- a/src/browser/server-context.remote-tab-ops.test.ts
+++ b/src/browser/server-context.remote-tab-ops.test.ts
@@ -1,16 +1,29 @@
-import { afterEach, describe, expect, it, vi } from "vitest";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from "vitest";
 import type { BrowserServerState } from "./server-context.js";
 import * as cdpModule from "./cdp.js";
 import * as pwAiModule from "./pw-ai-module.js";
 import { createBrowserRouteContext } from "./server-context.js";
 
+const chromeUserDataDir = vi.hoisted(() => ({ dir: "/tmp/openclaw" }));
+
+beforeAll(async () => {
+  chromeUserDataDir.dir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-chrome-user-data-"));
+});
+
+afterAll(async () => {
+  await fs.rm(chromeUserDataDir.dir, { recursive: true, force: true });
+});
+
 vi.mock("./chrome.js", () => ({
   isChromeCdpReady: vi.fn(async () => true),
   isChromeReachable: vi.fn(async () => true),
   launchOpenClawChrome: vi.fn(async () => {
     throw new Error("unexpected launch");
   }),
-  resolveOpenClawUserDataDir: vi.fn(() => "/tmp/openclaw"),
+  resolveOpenClawUserDataDir: vi.fn(() => chromeUserDataDir.dir),
   stopOpenClawChrome: vi.fn(async () => {}),
 }));
 
diff --git a/src/browser/server.agent-contract-form-layout-act-commands.test.ts b/src/browser/server.agent-contract-form-layout-act-commands.test.ts
index 2c5c223474..c4f44ed9c9 100644
--- a/src/browser/server.agent-contract-form-layout-act-commands.test.ts
+++ b/src/browser/server.agent-contract-form-layout-act-commands.test.ts
@@ -1,6 +1,9 @@
+import fs from "node:fs/promises";
 import { type AddressInfo, createServer } from "node:net";
+import os from "node:os";
+import path from "node:path";
 import { fetch as realFetch } from "undici";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
 
 let testPort = 0;
 let cdpBaseUrl = "";
@@ -62,6 +65,16 @@ const pwMocks = vi.hoisted(() => ({
   waitForViaPlaywright: vi.fn(async () => {}),
 }));
 
+const chromeUserDataDir = vi.hoisted(() => ({ dir: "/tmp/openclaw" }));
+
+beforeAll(async () => {
+  chromeUserDataDir.dir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-chrome-user-data-"));
+});
+
+afterAll(async () => {
+  await fs.rm(chromeUserDataDir.dir, { recursive: true, force: true });
+});
+
 function makeProc(pid = 123) {
   const handlers = new Map<string, Array<(...args: unknown[]) => void>>();
   return {
@@ -116,13 +129,13 @@ vi.mock("./chrome.js", () => ({
     return {
       pid: 123,
       exe: { kind: "chrome", path: "/fake/chrome" },
-      userDataDir: "/tmp/openclaw",
+      userDataDir: chromeUserDataDir.dir,
       cdpPort: profile.cdpPort,
       startedAt: Date.now(),
       proc,
     };
   }),
-  resolveOpenClawUserDataDir: vi.fn(() => "/tmp/openclaw"),
+  resolveOpenClawUserDataDir: vi.fn(() => chromeUserDataDir.dir),
   stopOpenClawChrome: vi.fn(async () => {
     reachable = false;
   }),
diff --git a/src/browser/server.agent-contract-snapshot-endpoints.test.ts b/src/browser/server.agent-contract-snapshot-endpoints.test.ts
index 3d84311046..b90924e59f 100644
--- a/src/browser/server.agent-contract-snapshot-endpoints.test.ts
+++ b/src/browser/server.agent-contract-snapshot-endpoints.test.ts
@@ -1,6 +1,9 @@
+import fs from "node:fs/promises";
 import { type AddressInfo, createServer } from "node:net";
+import os from "node:os";
+import path from "node:path";
 import { fetch as realFetch } from "undici";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
 import { DEFAULT_AI_SNAPSHOT_MAX_CHARS } from "./constants.js";
 
 let testPort = 0;
@@ -61,6 +64,16 @@ const pwMocks = vi.hoisted(() => ({
   waitForViaPlaywright: vi.fn(async () => {}),
 }));
 
+const chromeUserDataDir = vi.hoisted(() => ({ dir: "/tmp/openclaw" }));
+
+beforeAll(async () => {
+  chromeUserDataDir.dir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-chrome-user-data-"));
+});
+
+afterAll(async () => {
+  await fs.rm(chromeUserDataDir.dir, { recursive: true, force: true });
+});
+
 function makeProc(pid = 123) {
   const handlers = new Map<string, Array<(...args: unknown[]) => void>>();
   return {
@@ -114,13 +127,13 @@ vi.mock("./chrome.js", () => ({
     return {
       pid: 123,
       exe: { kind: "chrome", path: "/fake/chrome" },
-      userDataDir: "/tmp/openclaw",
+      userDataDir: chromeUserDataDir.dir,
       cdpPort: profile.cdpPort,
       startedAt: Date.now(),
       proc,
     };
   }),
-  resolveOpenClawUserDataDir: vi.fn(() => "/tmp/openclaw"),
+  resolveOpenClawUserDataDir: vi.fn(() => chromeUserDataDir.dir),
   stopOpenClawChrome: vi.fn(async () => {
     reachable = false;
   }),
diff --git a/src/browser/server.post-tabs-open-profile-unknown-returns-404.test.ts b/src/browser/server.post-tabs-open-profile-unknown-returns-404.test.ts
index 9ed16d6f3b..8c4612acb1 100644
--- a/src/browser/server.post-tabs-open-profile-unknown-returns-404.test.ts
+++ b/src/browser/server.post-tabs-open-profile-unknown-returns-404.test.ts
@@ -1,6 +1,9 @@
+import fs from "node:fs/promises";
 import { type AddressInfo, createServer } from "node:net";
+import os from "node:os";
+import path from "node:path";
 import { fetch as realFetch } from "undici";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
 
 let testPort = 0;
 let _cdpBaseUrl = "";
@@ -60,6 +63,16 @@ const pwMocks = vi.hoisted(() => ({
   waitForViaPlaywright: vi.fn(async () => {}),
 }));
 
+const chromeUserDataDir = vi.hoisted(() => ({ dir: "/tmp/openclaw" }));
+
+beforeAll(async () => {
+  chromeUserDataDir.dir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-chrome-user-data-"));
+});
+
+afterAll(async () => {
+  await fs.rm(chromeUserDataDir.dir, { recursive: true, force: true });
+});
+
 function makeProc(pid = 123) {
   const handlers = new Map<string, Array<(...args: unknown[]) => void>>();
   return {
@@ -113,13 +126,13 @@ vi.mock("./chrome.js", () => ({
     return {
       pid: 123,
       exe: { kind: "chrome", path: "/fake/chrome" },
-      userDataDir: "/tmp/openclaw",
+      userDataDir: chromeUserDataDir.dir,
       cdpPort: profile.cdpPort,
       startedAt: Date.now(),
       proc,
     };
   }),
-  resolveOpenClawUserDataDir: vi.fn(() => "/tmp/openclaw"),
+  resolveOpenClawUserDataDir: vi.fn(() => chromeUserDataDir.dir),
   stopOpenClawChrome: vi.fn(async () => {
     reachable = false;
   }),