The Pragma
HTTP/1.0 general header is an implementation-specific header that may have various effects along the request-response chain. It is used for backwards compatibility with HTTP/1.0 caches where the Cache-Control
HTTP/1.1 header is not yet present.
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 it does behave 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 | {{Glossary("General header")}}, but response behavior is not specified and thus implementation-specific. |
---|---|
{{Glossary("Forbidden header name")}} | no |
{{Glossary("Simple response header", "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 releasing a cached copy.
Examples
Pragma: no-cache
Specifications
Specification | Title |
---|---|
{{RFC("7234", "Pragma", "5.4")}} | Hypertext Transfer Protocol (HTTP/1.1): Caching |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
{{Compat}}
See also
- {{HTTPHeader("Cache-Control")}}
- {{HTTPHeader("Expires")}}