206 Partial Content

Success: the request was received, understood and accepted.

When a server should send it. In answer to a request with a Range header the server can satisfy: one range with a Content-Range header, or several as multipart/byteranges. Static file servers such as nginx and Apache do this for you when Accept-Ranges: bytes is set.

Common causes. Video streaming, resumed downloads and download managers that fetch in pieces.

What to do. Nothing. If a resumed download is corrupt, the file probably changed on the server between requests.

Browsers and HTTP clients. Video and audio players use ranges to seek and stream; download managers use them to resume and to fetch in parallel. A server that ignores Range and sends 200 with the whole file is allowed, just slower.

Caching. Cacheable by default (RFC 9110 section 15.1). With no Cache-Control or Expires header, a cache may still store it and reuse it for a heuristic period, often 10% of the time since Last-Modified, so set Cache-Control explicitly if that is not what you want.

HTTP/1.1 206 Partial Content
Content-Range: bytes 0-1023/146515
Content-Length: 1024
Content-Type: video/mp4
Accept-Ranges: bytes

Partial Content

location /example {
    return 206 'Partial Content';
}

http_response_code(206);
echo 'Partial Content';
exit;

res.writeHead(206, { 'Content-Type': 'text/plain' });
res.end('Partial Content');

# in a view function
return 'Partial Content', 206