php - Maximum number of cookies allowed

Question

As far as Google searches tell me, the maximum allowed number of cookies depends very much on the browser, however I cannot find any recent data as to how much cookies are allowed on modern browsers.

I need to store a somewhat large number of user preferences in cookies (for not-yet-registered users), so what would be the best way of doing that? (Also, those cookies would be accessed both via javascript client-side and php server-side)

Answer 1

From the rfc:

• at least 300 cookies

• at least 4096 bytes per cookie (as measured by the size of the characters that comprise the cookie non-terminal in the syntax description of the Set-Cookie header)

• at least 20 cookies per unique host or domain name

Those are minimum requirements. The IE6 team didn't get that. Everything else is highly browser-specific. You'd better write a test-platform to test each browser. Test the maximum size and number with little incremental steps (and check if they still are readable).

Also, I seem to remember apache has a problem with huges numbers of cookies. Can't remember where i've seen that though.

Here is a little cookie-testing script: http://krijnhoetmer.nl/stuff/javascript/maximum-cookies/