What is the maximum size of a web browser's cookie's key?

Question

What is the maximum size of a web browser\'s cookie\'s key?

I know the maximum size of a cookie is 4KB, but does the key have a limitation as well?

Answer 1

Actually, RFC 2965, the document that defines how cookies work, specifies that there should be no maximum length of a cookie's key or value size, and encourages implementations to support arbitrarily large cookies. Each browser's implementation maximum will necessarily be different, so consult individual browser documentation.

See section 5.3, "Implementation Limits", in the RFC.