[Bug]: Since 1.58, UI mode is very unstable. E2E tests lag until the whole execution is done, etc...[/-]

[samixchoumi]

Version

1.58.0

Steps to reproduce

Seem to happen on every API/E2E projects (I use chrome and chromium).
When I execute a test, I now need to wait for the full execution if I want to be able to check some issue of a previous failing test.

Command to execute to launch UI mode : npx playwright test --ui
When it's opened, execute multiple test (like 10 tests in a row using 1 worker to better understand the issue), when the first one is done, try access request from this finished test, impossible, you're always kicked out.
Same if you want to follow the test execution of the current test. It's very laggy.

Reverting to 1.57.1 fix this wrong behavior, a bit sad as the new UI from 1.58 is really better.

Expected behavior

No laggy behavior when looking at a test execution as it was done on previous version.
Whereas the test execution is running or done.

Actual behavior

Too much lag/unfocus/weird behavior happening.
Belowis the video using 1.58.0 version. Take a look at my mouse moving normally while the UI don't work at all or is very very slow compared to 1.57 usage.

Playwright-slow-2026-01-30.a.16.54.04.zip

You can see that when the execution is done, then it works properly as before.

Additional context

More information from someone else that had the issue can be seen here : #39050 (comment)
Thanks @veykos for your comment, I think it's better to redirect it on this new topic.

Environment

System:
    OS: macOS 26.2
    CPU: (8) arm64 Apple M1 Pro
    Memory: 80.19 MB / 16.00 GB
  Binaries:
    Node: 22.14.0 - /opt/homebrew/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 11.7.0 - /opt/homebrew/bin/npm
    pnpm: 8.10.3 - /usr/local/bin/pnpm
  IDEs:
    VSCode: 1.106.3 - /opt/homebrew/bin/code
  Languages:
    Bash: 3.2.57 - /bin/bash
  npmPackages:
    @playwright/test: ^1.58.0 => 1.58.0 
    playwright-bdd: ^8.4.2 => 8.4.2 
    playwright-slack-report: ^1.1.100 => 1.1.100

[pavelfeldman]

Works perfectly fine here. Any idea on why your setup can be special?

[samixchoumi]

No idea, some colleagues that work on other projects have the same issue and decided to downgrade until it’s fixed to 1.57.1.

I checked what @veykos said about the RAM and it may be the same root cause. Like Chrome takes too much

[veykos]

I made a small repro: in this repo

I included the steps for repro but I will copy paste them here just in case:

1. Clone repo
2. Run npm ci
3. Run npm run test:ui to open the Playwright UI
4. Toggle open at least 2 test suites so you can see the underlying tests
5. Hover over the tests fast up and down the list -> you should see the process Google Chrome for testing go to 200%+ CPU usage
6. Run all the tests and do the same hovering up and down -> Usage goes to 500%+ and UI becomes extremely laggy even with these 'mock' tests
7. Comment out the projects array in playwright.config.ts, restart the Playwright UI, run step 6 again -> somehow there is less lag in the UI

In my main project we have projects setup exactly as in the reproduction repo - I decided to try the 'defaults' and somehow it's less laggy, even I would say running normally except of the huge use of CPU from the Google Chrome for Testing

I'm attaching 2 videos - the first one show how laggy the UI becomes. And this is just running extremely light tests, in my main project we have some heavy setup of fixtures where the UI just freezes. The second video shows the same experiment, but with projects array commented out.

Laggy.mp4

Not_laggy.mp4

Sorry for the heavily compressed video, GitHub has a limit of 10 MB, but the compression doesn't affect the framerate, this is exactly how the UI looks on my laptop too.

Please advice what system information should I share to help with the reproduction?

MacBook Pro 16 inch -
Apple M2 Max
64 GB Ram
macOS 15.7.2 (24G325)

EDIT: I see Playwright 1.58.1 was released, unfortunately the lag still exists.

[Tiggles]

I'm experiencing this after updating to 1.58.1. Performance seems to be affected by the browser window shown inside the UI.

Screen.Recording.2026-02-02.at.16.16.33.mov

[mcrapts]

Same here. UI performance is very bad compared to 1.57.0.

[dgozman]

#39129 is a speculative fix.

[samixchoumi]

@dgozman, it will be deployed on which version to take a look ? Le jeu. 5 févr. 2026 à 11:13, Dmitry Gozman ***@***.***> a écrit :

…

*dgozman* left a comment (microsoft/playwright#39058) <#39058 (comment)> #39129 <#39129> is a speculative fix. — Reply to this email directly, view it on GitHub <#39058 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFJFCGEOHN3BC67MIGT3SFT4KMJWJAVCNFSM6AAAAACTOZ45H2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQNJSGUYTENZWG4> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[dgozman]

Could someone affected please try the @next canary release to verify that the problem is fixed there? We want to be sure before releasing v1.58.2.

[veykos]

Just tested this and seems like the issue is fixed. I installed @playwright/test@next and received:

version: 1.59.0-alpha-1770286317000

All of the lag in the UI - slow scrolling through timeline, test list, step list, is gone. Also the CPU use is back to normal, I no longer see spikes. UI seems as responsive as in version 1.57.

Thank you for your quick response and fix.

[dgozman]

This should be fixed in the latest v1.58.2 release. Thank you for filing!