POST data: where is it kept client side?

[geekpie]

If I send some POST data via a submit button, browse around elsewhere on the web, then return to the page where I POSTed and refresh, I am warned the POST data will be sent again.

Where has the post data been stored in the meantime?

[drhowarddrfine]

On your computer in cache.

[geekpie]

On your computer in cache.

But if I Control->F5 Refresh, the browser reloads from the origin server, not its cache. But it remembers what the POST data was for the Request. That hasn't been stored in cache because I can wipe the browser cache and it still knows what the POST data was.

[geekpie]

are files in your local browser cache actually written to your hard-disk or are they kept in memory?

[drhowarddrfine]

In that case, it is stored in cookies on your computer. Long term, that would be saved on your hard drive.

[geekpie]

I'm trying to understand the browser cache more generally now. What I'm thinking is it must be not just a store of files (in memory or on the hard-drive?: I don't know) but also a store of instructions for want of a better word sent out by the browser in the form of its requests. Otherwise how would the browser know that a particular request was a POST rather than GET when you Back-ed to the page and did a Control F5 refresh?