diff --git a/package-lock.json b/package-lock.json
index ded8822a7cfd8..5465dbfc0476c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1228,7 +1228,6 @@
       "cpu": [
         "ppc64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1245,7 +1244,6 @@
       "cpu": [
         "arm"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1262,7 +1260,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1279,7 +1276,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1296,7 +1292,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1313,7 +1308,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1330,7 +1324,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1347,7 +1340,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1364,7 +1356,6 @@
       "cpu": [
         "arm"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1381,7 +1372,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1398,7 +1388,6 @@
       "cpu": [
         "ia32"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1415,7 +1404,6 @@
       "cpu": [
         "loong64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1432,7 +1420,6 @@
       "cpu": [
         "mips64el"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1449,7 +1436,6 @@
       "cpu": [
         "ppc64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1466,7 +1452,6 @@
       "cpu": [
         "riscv64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1483,7 +1468,6 @@
       "cpu": [
         "s390x"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1500,7 +1484,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1517,7 +1500,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1534,7 +1516,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1551,7 +1532,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1568,7 +1548,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1585,7 +1564,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1602,7 +1580,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1619,7 +1596,6 @@
       "cpu": [
         "arm64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1636,7 +1612,6 @@
       "cpu": [
         "ia32"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1653,7 +1628,6 @@
       "cpu": [
         "x64"
       ],
-      "dev": true,
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4939,7 +4913,7 @@
       "version": "0.28.1",
       "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.28.1.tgz",
       "integrity": "sha512-HrJrvZv5ayxBzPfwphOoNzkzOIIlifzk0KJrGK2c8R4+LKpMtpYLQeUdjnwjWv/LZlkH2laZk+4w78pi99D4Vw==",
-      "dev": true,
+      "devOptional": true,
       "hasInstallScript": true,
       "license": "MIT",
       "bin": {
@@ -9762,6 +9736,14 @@
       },
       "engines": {
         "node": ">=20"
+      },
+      "peerDependencies": {
+        "esbuild": ">=0.21.5"
+      },
+      "peerDependenciesMeta": {
+        "esbuild": {
+          "optional": true
+        }
       }
     },
     "packages/playwright-browser-chromium": {
diff --git a/packages/playwright/package.json b/packages/playwright/package.json
index e2ae11459fcfc..7779613bcb4a4 100644
--- a/packages/playwright/package.json
+++ b/packages/playwright/package.json
@@ -46,5 +46,13 @@
   "license": "Apache-2.0",
   "dependencies": {
     "playwright-core": "1.65.0-next"
+  },
+  "peerDependencies": {
+    "esbuild": ">=0.21.5"
+  },
+  "peerDependenciesMeta": {
+    "esbuild": {
+      "optional": true
+    }
   }
 }
diff --git a/packages/playwright/src/transform/esbuildTransform.ts b/packages/playwright/src/transform/esbuildTransform.ts
new file mode 100644
index 0000000000000..0e26d0e000d10
--- /dev/null
+++ b/packages/playwright/src/transform/esbuildTransform.ts
@@ -0,0 +1,92 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import path from 'path';
+
+import { libPath } from '../package';
+
+import type * as esbuild from 'esbuild';
+import type { JsxOptions } from './babelBundle';
+
+export type Esbuild = typeof esbuild;
+
+export function loadEsbuild(): Esbuild {
+  try {
+    return require('esbuild');
+  } catch (error) {
+    throw new Error(`PLAYWRIGHT_EXPERIMENTAL_ESBUILD requires the "esbuild" package, install it with "npm install --save-dev esbuild"`, { cause: error });
+  }
+}
+
+export function esbuildTransform(esbuild: Esbuild, code: string, filename: string, isModule: boolean, useDefineForClassFields: boolean, jsx: JsxOptions | undefined): { code: string, map: any } {
+  const options = transformOptions(filename, isModule, useDefineForClassFields, jsx);
+  let result: esbuild.TransformResult;
+  try {
+    result = transformSync(esbuild, code, options);
+  } catch (error) {
+    throw toSyntaxError(error, code, filename);
+  }
+  return { code: result.code, map: JSON.parse(result.map) };
+}
+
+function transformOptions(filename: string, isModule: boolean, useDefineForClassFields: boolean, jsx: JsxOptions | undefined): esbuild.TransformOptions {
+  const ext = path.extname(filename);
+  const jsxMode = jsx?.jsx ?? 'react-jsx';
+  return {
+    sourcefile: filename,
+    loader: ext === '.tsx' ? 'tsx' : ['.ts', '.mts', '.cts'].includes(ext) ? 'ts' : 'jsx',
+    format: isModule ? 'esm' : 'cjs',
+    platform: 'node',
+    target: 'node' + process.versions.node.split('-')[0],
+    sourcemap: 'both',
+    jsx: jsxMode === 'react' ? 'transform' : 'automatic',
+    jsxDev: jsxMode === 'react-jsxdev',
+    jsxFactory: jsx?.jsxFactory,
+    jsxFragment: jsx?.jsxFragmentFactory,
+    jsxImportSource: jsx?.jsxImportSource,
+    tsconfigRaw: {
+      compilerOptions: {
+        useDefineForClassFields,
+        alwaysStrict: true,
+      },
+    },
+    logLevel: 'silent',
+  };
+}
+
+function transformSync(esbuild: Esbuild, code: string, options: esbuild.TransformOptions): esbuild.TransformResult {
+  try {
+    return esbuild.transformSync(code, options);
+  } catch (error) {
+    // Ctrl+C terminates esbuild's service process along with the whole process group.
+    if (!(error instanceof Error) || !/^The service (is no longer running|was stopped)/.test(error.message))
+      throw error;
+    void esbuild.stop();
+    return esbuild.transformSync(code, options);
+  }
+}
+
+function toSyntaxError(error: any, code: string, filename: string): Error {
+  const message: esbuild.Message | undefined = error?.errors?.[0];
+  if (!message?.location)
+    return error;
+  const { line, column } = message.location;
+  const { codeFrameColumns } = require(libPath('transform', 'babelBundle'));
+  const codeFrame = codeFrameColumns(code, { start: { line, column: column + 1 } });
+  const syntaxError = new SyntaxError(`${filename}: ${message.text} (${line}:${column})\n\n${codeFrame}`);
+  (syntaxError as any).loc = { line, column };
+  return syntaxError;
+}
diff --git a/packages/playwright/src/transform/transform.ts b/packages/playwright/src/transform/transform.ts
index ae1d8a3c72af0..0ee5f6e4fa8af 100644
--- a/packages/playwright/src/transform/transform.ts
+++ b/packages/playwright/src/transform/transform.ts
@@ -24,6 +24,7 @@ import { loadTsConfig } from './tsconfig-loader';
 import { libPath, packageJSON } from '../package';
 import { createFileMatcher, debugTest, fileIsModule, resolveImportSpecifierAfterMapping } from '../util';
 import * as cc from './compilationCache';
+import { esbuildTransform, loadEsbuild } from './esbuildTransform';
 import * as esmLoaderSync from './esmLoaderSync';
 import { addHook } from './pirates';
 import { PortTransport } from './portTransport';
@@ -230,7 +231,9 @@ export function shouldTransform(filename: string): boolean {
 }
 
 export function transformHook(originalCode: string, filename: string, moduleUrl?: string): { code: string, serializedCache?: any } {
+  const esbuild = process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD ? loadEsbuild() : undefined;
   const hasPreprocessor =
+    !esbuild &&
     process.env.PW_TEST_SOURCE_TRANSFORM &&
     process.env.PW_TEST_SOURCE_TRANSFORM_SCOPE &&
     process.env.PW_TEST_SOURCE_TRANSFORM_SCOPE.split(pathSeparator).some(f => filename.startsWith(f));
@@ -239,11 +242,17 @@ export function transformHook(originalCode: string, filename: string, moduleUrl?
   const jsx = tsconfigs.find(tsconfig => tsconfig.jsx)?.jsx;
   // Without "target", tsc defaults to the latest one, which defines class fields.
   const useDefineForClassFields = tsconfigs.find(tsconfig => tsconfig.useDefineForClassFields !== undefined)?.useDefineForClassFields ?? true;
-  const hash = calculateHash(originalCode, filename, !!moduleUrl, pluginsEpilogue, useDefineForClassFields, jsx);
+  const hash = calculateHash(originalCode, filename, !!moduleUrl, pluginsEpilogue, useDefineForClassFields, jsx, esbuild?.version);
   const { cachedCode, addToCache, serializedCache } = cc.getFromCompilationCache(filename, hash, moduleUrl);
   if (cachedCode !== undefined)
     return { code: cachedCode, serializedCache };
 
+  if (esbuild) {
+    const { code, map } = esbuildTransform(esbuild, originalCode, filename, !!moduleUrl, useDefineForClassFields, jsx);
+    const added = addToCache!(code, map);
+    return { code, serializedCache: added.serializedCache };
+  }
+
   // We don't use any browserslist data, but babel checks it anyway.
   // Silence the annoying warning.
   process.env.BROWSERSLIST_IGNORE_OLD_DATA = 'true';
@@ -257,7 +266,7 @@ export function transformHook(originalCode: string, filename: string, moduleUrl?
   return { code, serializedCache: added.serializedCache };
 }
 
-function calculateHash(content: string, filePath: string, isModule: boolean, pluginsEpilogue: BabelPlugin[], useDefineForClassFields: boolean, jsx: JsxOptions | undefined): string {
+function calculateHash(content: string, filePath: string, isModule: boolean, pluginsEpilogue: BabelPlugin[], useDefineForClassFields: boolean, jsx: JsxOptions | undefined, esbuildVersion: string | undefined): string {
   const hash = crypto.createHash('sha1')
       .update(isModule ? 'esm' : 'no_esm')
       .update(content)
@@ -266,6 +275,7 @@ function calculateHash(content: string, filePath: string, isModule: boolean, plu
       .update(pluginsEpilogue.map(p => p[0]).join(','))
       .update(useDefineForClassFields ? 'define' : 'assign')
       .update(jsx ? JSON.stringify(jsx) : '')
+      .update(esbuildVersion ? 'esbuild@' + esbuildVersion : '')
       .digest('hex');
   return hash;
 }
diff --git a/tests/library/trace-viewer.spec.ts b/tests/library/trace-viewer.spec.ts
index 18b251dbc234f..bc9225a46cb45 100644
--- a/tests/library/trace-viewer.spec.ts
+++ b/tests/library/trace-viewer.spec.ts
@@ -432,7 +432,7 @@ test('should show params and return value', async ({ showTraceViewer }) => {
     /Evaluate/,
     /start:[\d\.]+m?s/,
     /duration:[\d]+ms/,
-    /expression:"\({↵    a↵  }\) => {↵    console\.log\(\'Info\'\);↵    console\.warn\(\'Warning\'\);↵    console/,
+    /expression:"\({[↵\s]*a[↵\s]*}\) => {↵\s*console\.log\(['"]Info['"]\);↵\s*console\.warn\(['"]Warning['"]\);↵\s*console/,
     'isFunction:true',
     'arg:{"a":"paramA","b":4}',
     'value:"return paramA"'
diff --git a/tests/page/page-evaluate-callback.spec.ts b/tests/page/page-evaluate-callback.spec.ts
index 1c4edf7100f22..9862dbe69d8cd 100644
--- a/tests/page/page-evaluate-callback.spec.ts
+++ b/tests/page/page-evaluate-callback.spec.ts
@@ -19,7 +19,7 @@ import { test as it, expect } from './pageTest';
 
 it('should throw without the exposeFunctions option', async ({ page }) => {
   await expect(page.evaluate(({ cb }) => cb(), { cb: () => {} }))
-      .rejects.toThrow(/Attempting to serialize unexpected value at position "cb": \(\) => {}/);
+      .rejects.toThrow(/Attempting to serialize unexpected value at position "cb": \(\) => {\s*}/);
 });
 
 it('should call a function passed as an argument', async ({ page }) => {
diff --git a/tests/page/page-evaluate.spec.ts b/tests/page/page-evaluate.spec.ts
index 30cd7a3462c93..3744ac57eaa51 100644
--- a/tests/page/page-evaluate.spec.ts
+++ b/tests/page/page-evaluate.spec.ts
@@ -482,22 +482,22 @@ it('should throw for too deep reference chain 2', {
 
 it('should throw usable message for unserializable shallow function', async ({ page }) => {
   await expect(() => page.evaluate(arg => arg, () => { }))
-      .rejects.toThrow(/Attempting to serialize unexpected value: \(\) => {}/);
+      .rejects.toThrow(/Attempting to serialize unexpected value: \(\) => {\s*}/);
 });
 
 it('should throw usable message for unserializable object one deep function', async ({ page }) => {
   await expect(() => page.evaluate(arg => arg, { aProperty: () => { } }))
-      .rejects.toThrow(/Attempting to serialize unexpected value at position "aProperty": \(\) => {}/);
+      .rejects.toThrow(/Attempting to serialize unexpected value at position "aProperty": \(\) => {\s*}/);
 });
 
 it('should throw usable message for unserializable object nested function', async ({ page }) => {
   await expect(() => page.evaluate(arg => arg, { a: { inner: { property: () => { } } } }))
-      .rejects.toThrow(/Attempting to serialize unexpected value at position "a\.inner\.property": \(\) => {}/);
+      .rejects.toThrow(/Attempting to serialize unexpected value at position "a\.inner\.property": \(\) => {\s*}/);
 });
 
 it('should throw usable message for unserializable array nested function', async ({ page }) => {
   await expect(() => page.evaluate(arg => arg, { a: { inner: ['firstValue', { property: () => { } }] } }))
-      .rejects.toThrow(/Attempting to serialize unexpected value at position "a\.inner\[1\]\.property": \(\) => {}/);
+      .rejects.toThrow(/Attempting to serialize unexpected value at position "a\.inner\[1\]\.property": \(\) => {\s*}/);
 });
 
 it('should alias Window, Document and Node', async ({ page }) => {
diff --git a/tests/playwright-test/babel.spec.ts b/tests/playwright-test/babel.spec.ts
index 6d6c1bfa8bd5e..ebb480c910c91 100644
--- a/tests/playwright-test/babel.spec.ts
+++ b/tests/playwright-test/babel.spec.ts
@@ -234,6 +234,7 @@ for (const type of ['module', undefined]) {
       description: 'https://github.com/microsoft/playwright/issues/32659'
     }
   }, async ({ runInlineTest }) => {
+    test.skip(type === 'module' && !!process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD, 'esbuild drops "assert" import attributes');
     const result = await runInlineTest({
       'playwright.config.ts': `
       import packageJSON from './package.json' assert { type: 'json' };
@@ -257,6 +258,7 @@ for (const type of ['module', undefined]) {
 }
 
 test('should allow overwriting exports of a transpiled module', async ({ runInlineTest }) => {
+  test.skip(!!process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD, 'esbuild exports are getters');
   const result = await runInlineTest({
     'util.ts': `
       export function greet() { return 'real'; }
@@ -281,6 +283,7 @@ test('should allow overwriting exports of a transpiled module', async ({ runInli
 });
 
 test('should read undefined from an uninitialized import in a cycle', async ({ runInlineTest }) => {
+  test.skip(!!process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD, 'esbuild throws on uninitialized imports');
   const result = await runInlineTest({
     'a.ts': `
       import './b';
@@ -306,6 +309,7 @@ test('should read undefined from an uninitialized import in a cycle', async ({ r
 });
 
 test('should parse generic arrow functions in tsx', async ({ runInlineTest }) => {
+  test.skip(!!process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD, 'esbuild does not parse generic arrow functions in tsx');
   const result = await runInlineTest({
     'example.spec.tsx': `
       import { test, expect } from '@playwright/test';
@@ -322,6 +326,7 @@ test('should parse generic arrow functions in tsx', async ({ runInlineTest }) =>
 });
 
 test('should reject import.meta in commonjs', async ({ runInlineTest }) => {
+  test.skip(!!process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD, 'esbuild replaces import.meta with {}');
   const result = await runInlineTest({
     'example.spec.ts': `
       import { test, expect } from '@playwright/test';
diff --git a/tests/playwright-test/esbuild.spec.ts b/tests/playwright-test/esbuild.spec.ts
new file mode 100644
index 0000000000000..4e3d2df2811f8
--- /dev/null
+++ b/tests/playwright-test/esbuild.spec.ts
@@ -0,0 +1,175 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { test, expect, parseTestRunnerOutput } from './playwright-test-fixtures';
+
+const env = { PLAYWRIGHT_EXPERIMENTAL_ESBUILD: '1' };
+
+test('should transpile typescript', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'tsconfig.json': `{
+      "compilerOptions": { "jsx": "react", "jsxFactory": "h" },
+    }`,
+    'a.spec.ts': `
+      import { test, expect } from '@playwright/test';
+
+      enum Direction { Up = 1, Down }
+      namespace Shapes { export const sides = 4; }
+      namespace Shapes { export const corners = sides; }
+
+      function tagged(value: any, context: ClassMethodDecoratorContext) {
+        return function (this: any) { return 'tagged:' + value.call(this); };
+      }
+
+      class Base {
+        page: string;
+        constructor(page: string) { this.page = page; }
+      }
+
+      class LoginPage extends Base {
+        declare page: string;
+        readonly title = this.page + '-title';
+        constructor(page: string, private readonly user = 'admin') { super(page); }
+        @tagged name() { return this.user; }
+      }
+
+      test('works', () => {
+        expect(Direction.Down).toBe(2);
+        expect(Shapes.corners).toBe(4);
+        const loginPage = new LoginPage('login');
+        expect(loginPage.page).toBe('login');
+        expect(loginPage.title).toBe('login-title');
+        expect(loginPage.name()).toBe('tagged:admin');
+      });
+    `,
+    'b.spec.tsx': `
+      import { test, expect } from '@playwright/test';
+      const h = (tag: string, props: any, ...children: any[]) => ({ tag, props, children });
+      test('jsx', () => {
+        expect(<div id="x">text</div>).toEqual({ tag: 'div', props: { id: 'x' }, children: ['text'] });
+      });
+    `,
+  }, {}, env);
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(2);
+});
+
+test('should assign class fields for older targets', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'tsconfig.json': JSON.stringify({ compilerOptions: { target: 'ES2021' } }),
+    'a.spec.ts': `
+      import { test, expect } from '@playwright/test';
+
+      class Base {
+        redeclared = 'base';
+        setterCalls: string[] = [];
+        set overridden(value: string) { this.setterCalls.push(value); }
+      }
+
+      class Derived extends Base {
+        redeclared: string;
+        overridden = 'derived';
+        fromParameter = this.parameter + '-field';
+        constructor(private parameter: string) { super(); }
+      }
+
+      test('works', () => {
+        const derived = new Derived('parameter');
+        expect(derived.redeclared).toBe('base');
+        expect(derived.setterCalls).toEqual(['derived']);
+        expect(derived.fromParameter).toBe('parameter-field');
+      });
+    `,
+  }, {}, env);
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(1);
+});
+
+test('should map locations to sources', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'a.spec.ts': `
+      import { test, expect } from '@playwright/test';
+      enum Answer { Yes = 'yes' }
+      test('fails', () => {
+        expect(Answer.Yes as string).toBe('no');
+      });
+    `,
+  }, { reporter: 'list' }, env);
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain('a.spec.ts:4:7 › fails');
+  expect(result.output).toContain(`> 5 |         expect(Answer.Yes as string).toBe('no');`);
+  expect(result.output).toContain('a.spec.ts:5:38');
+});
+
+test('should support ESM packages', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'package.json': `{ "type": "module" }`,
+    'playwright.config.ts': `
+      import type { PlaywrightTestConfig } from '@playwright/test';
+      const config: PlaywrightTestConfig = { projects: [{ name: 'esm' }] };
+      export default config;
+    `,
+    'helper.ts': `
+      export enum Color { Red = 'red' }
+      export class Box { constructor(readonly color: Color) {} }
+    `,
+    'a.spec.ts': `
+      import { test, expect } from '@playwright/test';
+      import { Box, Color } from './helper';
+      test('works', () => {
+        expect(new Box(Color.Red).color).toBe('red');
+      });
+    `,
+  }, {}, env);
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(1);
+});
+
+test('should transpile global teardown after sigint', async ({ interactWithTestRunner }) => {
+  test.skip(process.platform === 'win32', 'No sending SIGINT on Windows');
+
+  const testProcess = await interactWithTestRunner({
+    'playwright.config.ts': `
+      export default {
+        globalSetup: './globalSetup.ts',
+        globalTeardown: './globalTeardown.ts',
+      };
+    `,
+    'globalSetup.ts': `
+      export default () => {
+        console.log('Global setup');
+        console.log('%%SEND-SIGINT%%');
+        return new Promise(f => setTimeout(f, 30000));
+      };
+    `,
+    'globalTeardown.ts': `
+      export default (): void => {
+        console.log('Global teardown');
+      };
+    `,
+    'a.spec.ts': `
+      import { test } from '@playwright/test';
+      test('test', async () => {});
+    `,
+  }, { workers: 1 }, env);
+  await testProcess.waitForOutput('%%SEND-SIGINT%%');
+  process.kill(-testProcess.process.pid!, 'SIGINT');
+  const { exitCode } = await testProcess.exited;
+  expect(exitCode).toBe(130);
+
+  const result = parseTestRunnerOutput(testProcess.output);
+  expect(result.output).toContain('Global teardown');
+});
diff --git a/tests/playwright-test/list-mode.spec.ts b/tests/playwright-test/list-mode.spec.ts
index 1388b38dd9e30..ea052d3adada6 100644
--- a/tests/playwright-test/list-mode.spec.ts
+++ b/tests/playwright-test/list-mode.spec.ts
@@ -193,7 +193,7 @@ test('should report errors with location', async ({ runInlineTest }) => {
   expect(JSON.parse(result.outputLines[0])).toEqual({
     file: expect.stringContaining('a.test.js'),
     line: 3,
-    column: 9,
+    column: expect.any(Number),
   });
 });
 
diff --git a/tests/playwright-test/loader.spec.ts b/tests/playwright-test/loader.spec.ts
index 8b36bbcaf3a79..96d2bb98b7e6d 100644
--- a/tests/playwright-test/loader.spec.ts
+++ b/tests/playwright-test/loader.spec.ts
@@ -63,11 +63,11 @@ test('should return the location of a syntax error with deep stack', async ({ ru
     `,
   });
   expect(result.exitCode).toBe(1);
-  expect(result.output).toContain('qux.ts:2:7');
-  expect(result.output).toContain('baz.ts:2:7');
-  expect(result.output).toContain('bar.ts:2:7');
-  expect(result.output).toContain('foo.ts:2:7');
-  expect(result.output).toContain('test.spec.ts:2:7');
+  expect(result.output).toContain('qux.ts:2:');
+  expect(result.output).toContain('baz.ts:2:');
+  expect(result.output).toContain('bar.ts:2:');
+  expect(result.output).toContain('foo.ts:2:');
+  expect(result.output).toContain('test.spec.ts:2:');
 });
 
 test('should print an improper error', async ({ runInlineTest }) => {
diff --git a/tests/playwright-test/test-server.spec.ts b/tests/playwright-test/test-server.spec.ts
index 9febdbe66a8b8..9d1fe101337e8 100644
--- a/tests/playwright-test/test-server.spec.ts
+++ b/tests/playwright-test/test-server.spec.ts
@@ -208,7 +208,7 @@ test('find related test files errors', async ({ startTestServer, writeFiles }) =
   const aSpecTs = test.info().outputPath('a.spec.ts');
   const result = await testServerConnection.findRelatedTestFiles({ files: [aSpecTs] });
   expect(result).toEqual({ testFiles: [], errors: [
-    expect.objectContaining({ message: expect.stringContaining(`Identifier 'a' has already been declared`) }),
+    expect.objectContaining({ message: expect.stringContaining(process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD ? `The symbol "a" has already been declared` : `Identifier 'a' has already been declared`) }),
     expect.objectContaining({ message: expect.stringContaining(`No tests found`) }),
   ] });
 
diff --git a/tests/playwright-test/ui-mode-test-output.spec.ts b/tests/playwright-test/ui-mode-test-output.spec.ts
index e0d12e63409dd..7f9256aeed506 100644
--- a/tests/playwright-test/ui-mode-test-output.spec.ts
+++ b/tests/playwright-test/ui-mode-test-output.spec.ts
@@ -29,7 +29,7 @@ test('should print load errors', async ({ runUITest }) => {
     `,
   });
   await page.getByTitle('Toggle output').click();
-  await expect(page.getByTestId('output')).toContainText(`Unexpected reserved word 'await'`);
+  await expect(page.getByTestId('output')).toContainText(process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD ? `"await" can only be used inside an "async" function` : `Unexpected reserved word 'await'`);
 });
 
 test('should work after theme switch', async ({ runUITest, writeFiles }) => {
@@ -190,12 +190,12 @@ test('should format console messages in page', async ({ runUITest }, testInfo) =
 
   await expect(page.locator('.console-tab')).toMatchAriaSnapshot(`
     - listbox:
-      - option /<anonymous>:1 Object/
-      - option /<anonymous>:4 Date/
-      - option /<anonymous>:5 Regex/
-      - option /<anonymous>:6 Number 0 one 2/
-      - option /<anonymous>:7 Download the React DevTools/
-      - option /<anonymous>:8 Array of values/
+      - option /<anonymous>:\\d+ Object/
+      - option /<anonymous>:\\d+ Date/
+      - option /<anonymous>:\\d+ Regex/
+      - option /<anonymous>:\\d+ Number 0 one 2/
+      - option /<anonymous>:\\d+ Download the React DevTools/
+      - option /<anonymous>:\\d+ Array of values/
       - option /Failed to load resource/
   `);
 
diff --git a/tests/playwright-test/ui-mode-test-source.spec.ts b/tests/playwright-test/ui-mode-test-source.spec.ts
index a22a142587863..21c49984c3ac9 100644
--- a/tests/playwright-test/ui-mode-test-source.spec.ts
+++ b/tests/playwright-test/ui-mode-test-source.spec.ts
@@ -154,7 +154,7 @@ test('should show syntax errors in file', async ({ runUITest }) => {
   await expect(
       page.locator('.CodeMirror-linewidget')
   ).toHaveText([
-    /Missing semicolon./
+    process.env.PLAYWRIGHT_EXPERIMENTAL_ESBUILD ? /Expected ";" but found "&"/ : /Missing semicolon./
   ]);
 });
 
diff --git a/utils/build/build.js b/utils/build/build.js
index 2a8d24c64f2d8..bd57605768304 100644
--- a/utils/build/build.js
+++ b/utils/build/build.js
@@ -755,6 +755,7 @@ steps.push(new CustomCallbackStep(assertCoreBundleHasNoNodeModules));
     external: [
       'playwright-core',
       'playwright-core/*',
+      'esbuild',
       '../package',
       '../globals',
       '../transform/esmLoader.js',
@@ -813,6 +814,7 @@ steps.push(new EsbuildStep({
     'playwright-core',
     'playwright-core/*',
     'playwright',
+    'esbuild',
     '../globals',
     '../package',
     '../utils',