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Headers: Pragma

Pragma header

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The HTTP Pragma header is an implementation-specific header that may have various effects along the request-response chain. This header serves for backwards compatibility with HTTP/1.0 caches that do not support the Cache-Control HTTP/1.1 header.

Note: The Pragma header is not specified for HTTP responses and is therefore not a reliable replacement for the 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 is implementation-specific).
Forbidden request header 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
HTTP Caching>
# field.pragma>

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS
Pragma 1 12 1 15 1 18 4 14 1 1.0 4.4 1

See also

  • Cache-Control
  • Expires

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https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Pragma

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