Playwright 1.65 Released: Bun Support, Error Reports and Updates

On November 5, Playwright 1.65 was released, bringing significant improvements for developers and QA engineers. The new version introduces experimental support for running tests via Bun, streamlines error reporting, and implements a mechanism for executing individual tests without parallel load. The update also impacts TypeScript handling, cookies, proxies, and accessibility checks.

• Playwright 1.65 launched on November 5 with experimental Bun test runner support.
• Added the onlyFailures parameter for HTML, JSON, and JUnit reports.
• Introduced -exclusive- built-in locking to isolate tests from parallel load.
• Dropped testing on Node.js 20, recommending versions 22, 24, or 26.

Bun Support in Playwright Test

Playwright Test now supports running tests through Bun. In this mode, Bun independently compiles TypeScript to JavaScript, allowing Playwright to bypass Babel and its compilation cache. The --bun flag must be explicitly used, otherwise the command will continue running via Node.js. The developers have verified the test runner with Bun 1.4.3 on Linux.

However, several limitations apply at this stage. File watch mode is unavailable, UI mode does not restart tests automatically, and --only-changed does not track dependencies via imports. Furthermore, custom ESM loaders and --tsconfig settings are not supported. Async frames are missing from stack traces, and API names are displayed without class names, impacting error messages.

New Reports and Exclusive Locking

Version 1.65 brings a new failure output format that displays errors and successful retries as tests execute. The onlyFailures parameter has been added for HTML, JSON, and JUnit reports, ensuring that only unexpected outcomes, flaky tests, and aborted scenarios are saved. This is particularly useful in CI environments with large test suites.

Another major addition is the built-in -exclusive- locking mechanism. It allows a specific test to execute when no other tests are running. This is invaluable for scenarios touching shared resources, such as server restarts or performance measurements, preventing parallel activity interference without serializing the entire test suite.

Behavior Changes and System Requirements

The update introduces several behavior changes that may affect existing codebases. Playwright now respects the useDefineForClassFields setting from tsconfig.json, which may cause TypeErrors if class fields are initialized via constructor parameters. Element interaction methods now wait for elements to stop being inert, and proxy credentials are no longer forwarded to target websites.

Regarding environment requirements, Playwright is no longer tested on Node.js 20, with developers recommending versions 22, 24, or 26. Official Docker images have replaced Node.js 24 with Node.js 26, Chromium has been updated to the latest patch version, and compatibility with Google Chrome 157 and Microsoft Edge 156 has been verified.

What This Means for Developers

Upgrading to Playwright 1.65 unlocks powerful tools for pipeline optimization and broadens runtime choices with Bun integration. However, teams should review their existing test suites for compatibility with the updated TypeScript settings, ARIA snapshots, and proxy configurations before completing the upgrade process.