vercel/next.js · error

A body was attempted to be set with a 204 statusCode for ${r

Error message

A body was attempted to be set with a 204 statusCode for ${req.url}, this is invalid and the body was ignored.\nSee more info here https://nextjs.org/docs/messages/invalid-api-status-body

What it means

Error "A body was attempted to be set with a 204 statusCode for ${req.url}, this is invalid and the body was ignored.\nSee more info here https://nextjs.org/docs/messages/invalid-api-status-body" thrown in vercel/next.js.

Source

Thrown at packages/next/src/server/api-utils/node/api-resolver.ts:71

 * Send `any` body to response
 * @param req request object
 * @param res response object
 * @param body of response
 */
function sendData(req: NextApiRequest, res: NextApiResponse, body: any): void {
  if (body === null || body === undefined) {
    res.end()
    return
  }

  // strip irrelevant headers/body
  if (res.statusCode === 204 || res.statusCode === 304) {
    res.removeHeader('Content-Type')
    res.removeHeader('Content-Length')
    res.removeHeader('Transfer-Encoding')

    if (process.env.NODE_ENV === 'development' && body) {
      console.warn(
        `A body was attempted to be set with a 204 statusCode for ${req.url}, this is invalid and the body was ignored.\n` +
          `See more info here https://nextjs.org/docs/messages/invalid-api-status-body`
      )
    }
    res.end()
    return
  }

  const contentType = res.getHeader('Content-Type')

  if (body instanceof Stream) {
    if (!contentType) {
      res.setHeader('Content-Type', 'application/octet-stream')
    }
    body.pipe(res)
    return
  }

View on GitHub (pinned to 0eb3775416)

Solutions

1. Do not send a body with a 204 status code; use `res.status(204).end()` without a payload.

When it happens

Trigger: Thrown at packages/next/src/server/api-utils/node/api-resolver.ts:71 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/cc7af36e5c9729bf. Report an issue: GitHub.