Tailwindcss 4.1.7 is too slow

[ameerhamzanawaz]

What version of Tailwind CSS are you using?
^4.1.7

What build tool (or framework if it abstracts the build tool) are you using?

"@tailwindcss/vite": "^4.1.7",
"vite": "^6.3.5"

What version of Node.js are you using?

v22.12.0

What browser are you using?

Chrome

What operating system are you using?

Windows

Reproduction URL

A Tailwind Play link or public GitHub repo that includes a minimal reproduction of the bug. Please do not link to your actual project, what we need instead is a minimal reproduction in a fresh project without any unnecessary code. This means it doesn't matter if your real project is private/confidential, since we want a link to a separate, isolated reproduction anyways.

A reproduction is required when filing an issue — any issue opened without a reproduction will be closed and you'll be asked to create a new issue that includes a reproduction. We're a small team and we can't keep up with the volume of issues we receive if we need to reproduce each issue from scratch ourselves.

Describe your issue

Describe the problem you're seeing, any important steps to reproduce and what behavior you expect instead.

Nothing fancy, i'm using Laravel 12, and tailwindcss v4, and it's taking mints more than 5 mints to load app.css file, if i remove @tailwindcss it's super fast even add/removing 'source' isn't solving the problem:

@import "tailwindcss";
/*Scan for utilities*/
@source "../views";

[RobinMalfait]

Hey!

Please attach a minimal reproduction so we can take a look.

My initial guess is that you are scanning a ton of files. We use .gitignore by default so a lot should be skipped already but you never know. You could run the build command with a DEBUG=* environment variable, it will write information to a file.

If you see a specific folder being scanned that should not be scanned, then you can use @source not … (https://tailwindcss.com/docs/detecting-classes-in-source-files#ignoring-specific-paths)

Even in our biggest projects Tailwind CSS v4 takes <1s so 5mins definitely doesn't make sense here.

[ameerhamzanawaz]

Thanks for your reply, but I think everyone is confused because docs are not clear, so it's best to add the following information on the installation page

https://tailwindcss.com/docs/detecting-classes-in-source-files

the following has fixed my problem, i just limit the tailwindcss to scan only views folder

@import "tailwindcss" source("../views");

[FragsterAt]

Do you have vendor, public/build, /public/hot, /public/storage and node_modules in your .gitignore?

[RobinMalfait]

The default files we scan are explained here: https://tailwindcss.com/docs/detecting-classes-in-source-files#which-files-are-scanned

If you want to ignore specific files/folders, checkout: https://tailwindcss.com/docs/detecting-classes-in-source-files#ignoring-specific-paths

If you want to opt-out of automatic source detection and be explicit yourself, checkout: https://tailwindcss.com/docs/detecting-classes-in-source-files#disabling-automatic-detection