# FAQ

## Does it work with ESLint?

No. oxlint-tailwindcss is an oxlint plugin, built on oxlint's JS plugin API and tested with oxlint
only. Install oxlint and add the plugin to `jsPlugins` in `.oxlintrc.json` — see [Setup](/setup).

## Which Tailwind versions does it support?

Tailwind CSS v4.1.15 and later. The plugin loads your project's own Tailwind engine, so the linter
and your build read the same design system; an older engine, a future major, or a major-version
drift from your build is reported with a message that says so. Tailwind v3 (`tailwind.config.js`)
isn't supported.

## Which rules run?

Only the ones you list under `rules`. oxlint's `categories` don't turn on a JS plugin's rules, so a
config with the plugin and no rules reports nothing. Start from the
[recommended config](/setup#3-recommended-starter-rule-set) and add rules from [the list](/rules/).

## Do I need an entry point?

The rules that read your design system — which classes exist, their order, their CSS — need
`settings.tailwindcss.entryPoint`, the CSS file where you `@import "tailwindcss"`. Without it they
report `designSystemUnavailable` once per file, with a hint. The other rules work without one, and
several get more precise with it. [The rule list](/rules/) says which is which.

## Does it lint Vue, Svelte and Astro files?

Their `<script>` blocks, and Astro's frontmatter — not the templates. oxlint hands JS plugins only
those parts of the file. [Vue, Svelte & Astro](/frameworks) shows what is and isn't linted.

## Why is a class that works reported as unknown?

`no-unknown-classes` knows Tailwind's classes and the ones your CSS defines — in the entry point and
the stylesheets of yours it imports, up to four `@import`s down, and a package's stylesheet it
imports. A class it reports that still works in the browser usually comes from CSS the entry point
doesn't import, one your app loads separately. Or it has no CSS at all and is a hook for JavaScript
or tests. Import that CSS from the entry point, or tell the rule about the class with
[`allowlist` or `ignorePrefixes`](/rules/no-unknown-classes#options).

## Does it support Tailwind plugins?

Any plugin your entry point loads — with `@plugin` or `@import` — is part of the design system the
rules read, so its classes are known like Tailwind's own. The test suite runs with
`@tailwindcss/typography`, `tailwindcss-animate` and `tw-animate-css`.

## How do I turn a rule off for one line?

With oxlint's comments, naming the rule:

```tsx
// oxlint-disable-next-line tailwindcss/no-unknown-classes
<div className="legacy-widget flex" />
```

## Why does `oxlint --fix` leave some problems?

oxlint applies one fix per class string per run. When several rules fix the same string — a
duplicate, extra whitespace and the order — each run applies one of them; run `oxlint --fix` again
until nothing changes.

## Does it replace prettier-plugin-tailwindcss or oxfmt's class sorting?

No, they work together. The formatter sorts classes, removes duplicates and collapses whitespace in
what it formats; this plugin checks correctness — unknown, conflicting, deprecated and runtime-built
classes, and more. Point both at the same CSS and they sort the same way: see [Interop](/interop).

## How does it compare with @shadcn/lint and better-tailwindcss?

They check different things: [Compared with other plugins](/comparison) shows what each one checks,
and the [benchmark](/benchmark) measures them on the same code — mistakes caught, false positives,
speed, and what their fixes do.

## Can I use it with @shadcn/lint?

Yes. [shadcn/ui and @shadcn/lint](/shadcn) shows who reports what and a combined config that reports
each problem once.

## I use eslint-plugin-better-tailwindcss. How do I switch?

Each of its rules has a counterpart here; the [migration guide](/migration/from-better-tailwindcss)
maps them and their settings, and walks through the switch.

## How do I make it fast in CI?

The design system is precomputed once per entry point and cached on disk. Keep that cache between
jobs — [Running in CI](/ci) has the `actions/cache` recipe.

## Does it work in a monorepo?

Yes: map each package's files to its CSS in the root config, or give each package its own
`.oxlintrc.json`. See [Monorepo](/monorepo).