Partial Content

The server is delivering only part of the resource, used for range requests.

206 Partial Content is the answer to a Range request: the server returns just the slice of bytes the client asked for, with a Content-Range header saying which slice. It's what makes video seeking, resumable downloads, and streaming large PDFs work. Lots of 206s for media files in your logs is normal and healthy.

What 206 looks like on the wire

GET /videos/intro.mp4 HTTP/1.1
Host: cdn.example.com
Range: bytes=0-1048575

HTTP/1.1 206 Partial Content
Content-Range: bytes 0-1048575/31457280
Content-Length: 1048576
Content-Type: video/mp4
Accept-Ranges: bytes

About 2xx Success

The request was received, understood, and accepted. This is what you want to see.

How to fix 206 Partial Content

If video seeking doesn't work, confirm the server sends Accept-Ranges: bytes and honors Range requests.
Check that a proxy or CDN in front isn't stripping the Range header.
If a resumed download fails, the file probably changed - validate with If-Range or restart the download.

Where it's defined

206 Partial Content is defined in RFC 9110 §15.3.7. MDN's 206 reference covers browser behavior and examples.