Pragma
The Pragma
HTTP/1.0 general header is an
implementation-specific header that may have various effects along the request-response
chain. This header serves for backwards compatibility with the HTTP/1.0 caches that do not have a
Cache-Control
HTTP/1.1 header.
Note: Pragma
is not specified for HTTP responses and is
therefore not a reliable replacement for the general HTTP/1.1
Cache-Control
header, although its behavior is the same as
Cache-Control: no-cache
if the Cache-Control
header field
is omitted in a request. Use Pragma
only for backwards compatibility with
HTTP/1.0 clients.
Header type | Request header, Response header (response behavior is not specified and thus implementation-specific). |
---|---|
Forbidden header name | no |
CORS-safelisted response header | yes |
Syntax
Pragma: no-cache
Directives
- no-cache
-
Same as
Cache-Control: no-cache
. Forces caches to submit the request to the origin server for validation before a cached copy is released.
Examples
Pragma: no-cache
Specifications
Specification |
---|
Hypertext Transfer Protocol (HTTP/1.1): Caching # header.pragma |
Browser compatibility
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