[App Router] CWV Avoid sending legacy JS to modern browsers - how to remove next.js polyfills

[abaracedo]

Summary

When I run Lighthouse on my application I get a warning to avoid serving legacy JS in modern browsers. Looking into the details I see the code references polyfills to Object.entries() and the @babel/plugin-transform-classes is used.

I'd tried to set a custom browserlist configuration to point to more up to date browser's versions and after running CWV I still get the same warning.

Is it possible to remove that polyfills?

Additional information

No response

Example

No response

[bbaymistery]

did u find solution
it is been 4 days i am struggling find out solution
i run into the same issue

[piersolenski]

Same issue after trying all the solutions on this thread

[marcoms]

I'm not 100% sure that Next is doing anything with the browserslist config, despite what it says in the docs here (https://nextjs.org/docs/architecture/supported-browsers#browserslist) unless I'm mistaken. I tried modifying the browserslist value in package.json to "ie >= 10" as an extreme example and the diff between the previous build JS and the next one is the same.

[Ayach90]

some news about this topic? I have the same issue

[gndelia]

There are some polyfills that can't be removed nor they plan to, you can check #77768

If you really need to get rid of those, patching next is one option. Though you have to really be sure about that...

[bbaymistery]

some news about this topic? I have the same issue

Any updates ? still geting this error and it kills my performance speed