What does the HTTP header Pragma: Public mean?

Question

It could be useful to know the context. – Skurmedel Dec 17 '09 at 10:45 — Skurmedel, Dec 17 '09 at 10:45

score 44 · Answer 1 · answered Dec 17 '09 at 10:46

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According to the standard, Pragma is implementation dependent (section 14.32), except for no-cache because of its wide use. Cache-Control (section 14.9) is the proper way to control caching. This is what the standard says for a Cache-Control: public:

Indicates that the response MAY be cached by any cache, even if it would normally be non-cacheable or cacheable only within a non- shared cache.

answered Dec 17 '09 at 10:46

Gonzalo

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Thanks but there are many instances of people coding so that a header is sent that contains only Pragma: Public. What does this mean to any major browser? – user185631 Dec 18 '09 at 11:14
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The same that "Cache-Control: public", ie, that they MAY cache the information in that response. – Gonzalo Dec 18 '09 at 17:36
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It means coders should stop using it because it's probably not serving any purpose – Anthony Jul 14 '14 at 06:49

score 11 · Answer 2 · edited May 23 '17 at 11:45

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Also, "Pragma: Public" is used in Google App Engine applications to enable caching of responses within its Edge Cache.

See Details on Google App Engine's caching proxy?

edited May 23 '17 at 11:45

Community

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answered Jan 23 '14 at 16:54

Andy Dennie

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score 8 · Answer 3 · answered Jun 02 '11 at 14:24

Useful when you come across this error: http://trac.edgewall.org/ticket/1020. IE 8 & less seems to like to cache things when they are on a SSL server. Putting 'Pragma:public' helps with: "Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later"

What does the HTTP header Pragma: Public mean?

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