HTTP 206 Partial Content

What It Means

The HTTP 206 Partial Content status code indicates that the server is successfully fulfilling a range request. The response contains only the portion of the resource specified by the Range header in the request.

Common Use Cases

Video streaming: Loading video segments as needed (seeking)
Resumable downloads: Continuing interrupted file downloads
PDF viewers: Loading specific pages on demand
Audio streaming: Jumping to specific timestamps

Example Request/Response

# Client requests bytes 0-1023 of a file
GET /video.mp4 HTTP/1.1
Host: cdn.example.com
Range: bytes=0-1023

# Server returns partial content
HTTP/1.1 206 Partial Content
Content-Type: video/mp4
Content-Length: 1024
Content-Range: bytes 0-1023/1048576
Accept-Ranges: bytes

[1024 bytes of video data]

Required Headers

Header	Purpose
Content-Range	Indicates which bytes are being returned and total size
Content-Length	Size of the partial content being returned
Accept-Ranges	Indicates server supports range requests (usually "bytes")

Range Header Formats

# First 500 bytes
Range: bytes=0-499

# Bytes from 500 to end
Range: bytes=500-

# Last 500 bytes
Range: bytes=-500

# Multiple ranges (multipart response)
Range: bytes=0-100, 200-300

Server Support

To check if a server supports range requests:

HEAD /large-file.zip HTTP/1.1

HTTP/1.1 200 OK
Accept-Ranges: bytes        ← Range requests supported
Content-Length: 104857600