next.js/errors/proxy-relative-urls.mdx

---
title: Proxy Relative URLs
---

## Why This Error Occurred

You are using a Proxy function that uses `Response.redirect(url)`, `NextResponse.redirect(url)` or `NextResponse.rewrite(url)` where `url` is a relative or an invalid URL. Prior to Next.js 12.1, we allowed passing relative URLs. However, constructing a request with `new Request(url)` or running `fetch(url)` when `url` is a relative URL **does not** work. For this reason and to bring consistency to Next.js Proxy, this behavior has been deprecated and now removed.

## Possible Ways to Fix It

To fix this error you must always pass absolute URL for redirecting and rewriting. There are several ways to get the absolute URL but the recommended way is to clone `NextURL` and mutate it:

```ts filename="proxy.ts"
import type { NextRequest } from 'next/server'
import { NextResponse } from 'next/server'

export function proxy(request: NextRequest) {
  const url = request.nextUrl.clone()
  url.pathname = '/dest'
  return NextResponse.rewrite(url)
}
```

Another way to fix this error could be to use the original URL as the base but this will not consider configuration like `basePath` or `locale`:

```ts filename="proxy.ts"
import type { NextRequest } from 'next/server'
import { NextResponse } from 'next/server'

export function proxy(request: NextRequest) {
  return NextResponse.rewrite(new URL('/dest', request.url))
}
```

You can also pass directly a string containing a valid absolute URL.

## Useful Links

- [URL Documentation](https://developer.mozilla.org/docs/Web/API/URL)
- [Response Documentation](https://developer.mozilla.org/docs/Web/API/Response)