Search code examples
httpcross-browserrfc

Maximum Cookie Size of current browsers (Year 2018)

From the django docs:

Both RFC 2109 and RFC 6265 state that user agents should support cookies of at least 4096 bytes. For many browsers this is also the maximum size.

Source: https://docs.djangoproject.com/en/2.1/ref/request-response/

Is this still valid today?

What is the maximum cookie size of current browsers?

Solution

  • The cookie spec definition in RFC6265 (April 2011) is the current RFC (No new draft and no new RFC) and is supported by all major browsers (IE,Chrome,Opera,Firefox) today.

    • At least 4096 bytes for the entire cookie (as measured by the sum of all of the cookie names, values, and attributes).

    • At least 50 cookies per domain, provided they don't go over the above limit.

    • At least 3000 cookies total.

    So all modern browsers support AT LEAST this. Any other limit values are a gamble

    See 6.1. Limits in https://datatracker.ietf.org/doc/rfc6265/ for more details