HTTP Status Codes

206 Partial Content

The server is returning a byte range rather than the whole resource — the mechanism behind resumable downloads and video/audio streaming with seeking.

What it means

When a client sends a Range header, a server that supports ranges replies 206 Partial Content with a Content-Range header describing which bytes are included. This lets downloads resume after interruption and lets media players seek without fetching the whole file.

HTTP EXCHANGE
> GET /video.mp4 HTTP/1.1
> Range: bytes=1048576-2097151

< HTTP/1.1 206 Partial Content
< Content-Range: bytes 1048576-2097151/9437184
< Content-Length: 1048576
< Accept-Ranges: bytes

Why it matters

  • It enables resumable downloads and efficient media streaming, saving bandwidth on seeks and retries.
  • Advertising Accept-Ranges: bytes lets clients and CDNs request only what they need.

Common mistakes

  • Ignoring the Range header and returning the whole 200 body, breaking seeking and resume.
  • Returning 206 without a correct Content-Range, confusing clients about which bytes arrived.

How WebInspect checks this

  • WebInspect reports Accept-Ranges support and how a server responds to range requests in its performance analysis.