How can I check which version of SWC is being used by Next.js?

[schardev]

A recent SWC version fixed a bug that’s been annoying me, so I wanted to see which version Next.js is using. But I couldn’t find a clear way to check. Lock files aren’t ideal either. Is there an easier way to find this?

[GaneshVarma1]

Hi @schardev 👋,

Method 1: Use npm ls

Run the following in your project directory:

npm ls @swc/core

This will output the exact version of @swc/core that is being used internally by Next.js.

If you're using yarn, you can run:

yarn why @swc/core

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Method 2: Inspect node_modules

You can also manually check:

cat node_modules/@swc/core/package.json | grep version

This will print the installed SWC version, assuming it's installed locally.

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Let me know if you’d like help checking a specific SWC feature or bug fix in your Next.js version!

Cheers 🚀

[icyJoseph]

You need to check the Cargo file, for example here:

• https://github.com/vercel/next.js/pull/81276/files

This was the 30.1.1 update - the question is though, which version is in the current stable?

• https://github.com/vercel/next.js/blob/v15.3.5/Cargo.toml#L299

This shows that swc_core in 15.3.5 is 21.0.1