vercel/next.js · error · ImageError

"url" parameter is valid but upstream response timed out

Error message

"url" parameter is valid but upstream response timed out

What it means

Timeout failure in fetchExternalImage: the upstream image fetch is wrapped with AbortSignal.timeout(7_000), and when the timer fires the fetch rejects with a TimeoutError. The catch block distinguishes it from other fetch errors and throws ImageError 504 so the client knows the URL was acceptable but the origin was too slow.

Solutions

1. Check that the upstream image server responds quickly; increase timeout or fix the upstream host.

When it happens

Trigger: The upstream image fetch times out.

Common situations: A slow or unreachable remote image server when optimizing remote images.

Understand the failure class

• Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

AI-assisted analysis of vercel/next.js@996f957c06 (2026-08-19). Data as JSON: /api/errors/0ec56a42e8229f2b. Report an issue: GitHub.

Appendix: source

Thrown at packages/next/src/server/image-optimizer.ts:559

        'upstream image',
        href,
        'hostname resolved to private IP',
        JSON.stringify(privateIps),
        'If this is expected and you understand SSRF risk, use images.dangerouslyAllowLocalIP = true to continue.'
      )
      throw new ImageError(400, '"url" parameter is not allowed')
    }
  }
  const res = await fetch(href, {
    signal: AbortSignal.timeout(7_000),
    redirect: 'manual',
  }).catch((err) => err as Error)

  if (res instanceof Error) {
    const err = res as Error
    if (err.name === 'TimeoutError') {
      Log.error('upstream image response timed out for', href)
      throw new ImageError(
        504,
        '"url" parameter is valid but upstream response timed out'
      )
    }
    throw err
  }

  const locationHeader = res.headers.get('Location')
  if (
    isRedirect(res.status) &&
    locationHeader &&
    URL.canParse(locationHeader, href)
  ) {
    if (count === 0) {
      Log.error('upstream image response had too many redirects', href)
      throw new ImageError(
        508,
        '"url" parameter is valid but upstream response is invalid'

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