Range
The
Range HTTP request header indicates the parts of a document that the server should return.
Several parts can be requested at the same time in one Range header, and the server may send back these ranges in a multipart document.
If the server sends back ranges, it uses the 206 Partial Content for the response.
If the ranges are invalid, the server returns the 416 Range Not Satisfiable error.
The server can also ignore the Range header and return the whole document with a 200 status code.
The header is a CORS-safelisted request header when the directive specifies a single byte range.
| Header type | Request header |
|---|---|
| Forbidden header name | no |
Syntax
http
Range: <unit>=<range-start>-
Range: <unit>=<range-start>-<range-end>
Range: <unit>=<range-start>-<range-end>, <range-start>-<range-end>
Range: <unit>=<range-start>-<range-end>, <range-start>-<range-end>, <range-start>-<range-end>
Range: <unit>=-<suffix-length>
Directives
- <unit>
-
The unit in which ranges are specified. This
bytesfor byte ranges (currently no other range units are registered). - <range-start>
-
An integer indicating the beginning of the request range, in the given unit.
- <range-end>
-
An integer indicating the end of the requested range, in the given unit. This value is optional and, if omitted, the end of the document is taken as the end of the range.
- <suffix-length>
-
An integer indicating the number of (given) units at the end of the file to return.
Examples
The following examples show how to make requests using the
Range header for CORS-safelisted requests, and for requesting multiple ranges.
Other examples can be found in the HTTP range requests guide.
Making CORS-safelisted requests
The
Range header is a CORS-safelisted request header when the value is a single byte range.
This means that it can be used in cross-origin requests without triggering a preflight request, which is useful for requesting media and resuming downloads.
This example requests the bytes from 100 to 200 of the resource:
http
Range: bytes=100-200
The following example requests the last 500 bytes of the resource:
http
Range: bytes=-500
Requesting multiple ranges
The following example requests three separate parts of a file, from
200-1000 (the first 800 bytes), 2000-6576 (the bytes from 2000 to 6576), and finally 19000-.
The ranges-specifier value 19000- specifies 19000 as the first position, and omits any last position in order to indicate that all bytes from 19000 onward are part of the third range.
http
Range: bytes=200-1000, 2000-6576, 19000-
This example requests the first 500 and last 500 bytes of the file.
The request may be rejected by the server if these ranges overlap (i.e. the file is less than 1000 bytes long).
http
Range: bytes=0-499, -500
Specifications
| Specification |
|---|
| HTTP Semantics # field.range |
Browser compatibility
Report problems with this compatibility data on GitHubChrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on iOS | Samsung Internet | WebView Android | |
|---|---|---|---|---|---|---|---|---|---|---|---|
CORS-safelisted request header with single range | |||||||||||
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