WordPress Playground is very slow

[fahimmurshed]

WordPress Playground feels very slow. Testing themes or experimenting with settings takes too much time, and creating an instant staging site becomes a long process. Please improve the speed and performance.

​https://playground.wordpress.net/

[fahimmurshed]

Errors

[dd32]

Hello @fahimmurshed,

Playground is loading an entire PHP Server & Database within your browser, that requires downloading a lot of data and also requires a lot of memory in your browser.

That will result in it being slow.

However, the team is working on performance and making it better all the time.

edit: It looks like you're importing a WXR, that'll also often be slower as it then needs to also download all the images/other assets included in the file. That can take some significant time in my experience.

I'm closing this ticket, as there's nothing actionable included.

For future reference, the Playground team manages their issues/code through this GitHub repository: ​https://github.com/WordPress/wordpress-playground

[dd32]

In 14520:

Trac: Add a hint for where the WordPress Playground is developed.

See #8074.

[fahimmurshed]

You are right. I am reviewing the theme (​https://themes.trac.wordpress.org/ticket/228910) and failed to open with Playground.

Log:

[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "importFile" step is deprecated. Use "importWxr" instead.
[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "pluginZipFile" option of the "installPlugin" step is deprecated. Use "pluginData" instead.
[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "themeZipFile" option of the "installTheme" step is deprecated. Use "themeData" instead.
[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "importFile" step is deprecated. Use "importWxr" instead.
[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "pluginZipFile" option of the "installPlugin" step is deprecated. Use "pluginData" instead.
[02-Sept-2025 04:53:20 UTC] JavaScript warn: The "themeZipFile" option of the "installTheme" step is deprecated. Use "themeData" instead.
[02-Sept-2025 04:53:28 UTC] JavaScript error: Error when executing the blueprint step #3 ({"step":"importWxr","file":{"resource":"url","url":"https://raw.githubusercontent.com/WordPress/theme-test-data/master/themeunittestdata.wordpress.xml","caption":"Downloading theme testing content"},"progress":{"caption":"Installing theme testing content"}}) : null function or function signature mismatch
Error: Error when executing the blueprint step #3 ({"step":"importWxr","file":{"resource":"url","url":"https://raw.githubusercontent.com/WordPress/theme-test-data/master/themeunittestdata.wordpress.xml","caption":"Downloading theme testing content"},"progress":{"caption":"Installing theme testing content"}}) : null function or function signature mismatch
    at Object.run (https://playground.wordpress.net/assets/index-DIhZc2Q0.js:988:149843)
    at async uE (https://playground.wordpress.net/assets/index-DIhZc2Q0.js:988:151509)
    at async AT (https://playground.wordpress.net/assets/index-DIhZc2Q0.js:988:152499)
    at async https://playground.wordpress.net/assets/main-C4mBj407.js:157:2449

[dd32]

Ahh yes, the Theme Review links are a little broken at present. See #8077

[fahimmurshed]

Great! Appreciate for the updates