gil-wiki/reference/4.api/5.kit/3.compatibility.md

---
title: "Compatibility"
description: Nuxt Kit provides a set of utilities to help you check the compatibility of your modules with different Nuxt versions.
links:
  - label: Source
    icon: i-simple-icons-github
    to: https://github.com/nuxt/nuxt/blob/main/packages/kit/src/compatibility.ts
    size: xs
---

Nuxt Kit utilities can be used in Nuxt 3, Nuxt 2 with Bridge and even Nuxt 2 without Bridge. To make sure your module is compatible with all versions, you can use the `checkNuxtCompatibility`, `assertNuxtCompatibility` and `hasNuxtCompatibility` functions. They will check if the current Nuxt version meets the constraints you provide. Also you can use `isNuxt2`, `isNuxt3` and `getNuxtVersion` functions for more granular checks.

## `checkNuxtCompatibility`

Checks if constraints are met for the current Nuxt version. If not, returns an array of messages. Nuxt 2 version also checks for `bridge` support.

### Usage

```ts twoslash
import { checkNuxtCompatibility, defineNuxtModule } from '@nuxt/kit'

export default defineNuxtModule({
  async setup (_options, nuxt) {
    const issues = await checkNuxtCompatibility({ nuxt: '^2.16.0' }, nuxt)
    if (issues.length) {
      console.warn('Nuxt compatibility issues found:\n' + issues.toString())
    } else {
      // do something
    }
  },
})
```

### Type

```ts
function checkNuxtCompatibility (constraints: NuxtCompatibility, nuxt?: Nuxt): Promise<NuxtCompatibilityIssues>
```

### Parameters

**`constraints`**: Version and builder constraints to check against. It accepts the following properties:

| Property | Type                                          | Required  | Description                                                                                                                                      |
| -------- | --------------------------------------------- | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `nuxt`   | `string`                                      | `false`   | Nuxt version in semver format. Versions may be defined in Node.js way, for example: `>=2.15.0 <3.0.0`.                                           |
| `bridge` | `Record<string, string \| false>`{lang="ts"}  | `false`   | Specifies version constraints or disables compatibility for specific Nuxt builders like `vite`, `webpack`, or `rspack`. Use `false` to disable.  |

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `assertNuxtCompatibility`

Asserts that constraints are met for the current Nuxt version. If not, throws an error with the list of issues as string.

### Type

```ts twoslash
// @errors: 2391
import type { Nuxt, NuxtCompatibility } from '@nuxt/schema'
// ---cut---
function assertNuxtCompatibility (constraints: NuxtCompatibility, nuxt?: Nuxt): Promise<true>
```

### Parameters

**`constraints`**: Version and builder constraints to check against. Refer to the [constraints table in `checkNuxtCompatibility`](/docs/4.x/api/kit/compatibility#parameters) for details.

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `hasNuxtCompatibility`

Checks if constraints are met for the current Nuxt version. Return `true` if all constraints are met, otherwise returns `false`. Nuxt 2 version also checks for `bridge` support.

### Usage

```ts twoslash
import { defineNuxtModule, hasNuxtCompatibility } from '@nuxt/kit'

export default defineNuxtModule({
  async setup (_options, nuxt) {
    const usingNewPostcss = await hasNuxtCompatibility({ nuxt: '^2.16.0' }, nuxt)
    if (usingNewPostcss) {
      // do something
    } else {
      // do something else
    }
  },
})
```

### Type

```ts
function hasNuxtCompatibility (constraints: NuxtCompatibility, nuxt?: Nuxt): Promise<boolean>
```

### Parameters

**`constraints`**: Version and builder constraints to check against. Refer to the [constraints table in `checkNuxtCompatibility`](/docs/4.x/api/kit/compatibility#parameters) for details.

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `isNuxtMajorVersion`

Check if current Nuxt instance is of specified major version

### Usage

```ts twoslash
import { defineNuxtModule, isNuxtMajorVersion } from '@nuxt/kit'

export default defineNuxtModule({
  setup () {
    if (isNuxtMajorVersion(3)) {
      // do something for Nuxt 3
    } else {
      // do something else for other versions
    }
  },
})
```

### Type

```ts
function isNuxtMajorVersion (major: number, nuxt?: Nuxt): boolean
```

### Parameters

**`major`**: Major version to check against.

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `isNuxt3`

Checks if the current Nuxt version is 3.x.

::note
Use `isNuxtMajorVersion(2, nuxt)` instead. This may be removed in \@nuxt/kit v5 or a future major version.
::

### Type

```ts
function isNuxt3 (nuxt?: Nuxt): boolean
```

### Parameters

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `isNuxt2`

Checks if the current Nuxt version is 2.x.

::note
Use `isNuxtMajorVersion(2, nuxt)` instead. This may be removed in \@nuxt/kit v5 or a future major version.
::

### Type

```ts
function isNuxt2 (nuxt?: Nuxt): boolean
```

### Parameters

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.

## `getNuxtVersion`

Returns the current Nuxt version.

### Type

```ts
function getNuxtVersion (nuxt?: Nuxt): string
```

### Parameters

**`nuxt`**: Nuxt instance. If not provided, it will be retrieved from the context via `useNuxt()` call.