Unless something has recently changed in the standards, there is no such thing as a default cookie lifetime. If a web site creates a cookie without defining the expiration time, it is to be kept until the end of the session (i.e. when the user closes the browser).
Note that browser extensions exist that can delete cookies early under certain conditions, such as when they are from a tab that hasn’t been used for an extended period of time.
Ok good to know, it does seem like there is some standard across browsers for a maximum cookie lifetime of 400 at least.
Do you have a cookie extension in specifc you would recommend?
400? Seconds or years?
Firefox has built-in cookie-deletion when you close the browser/tab, it’s under settings/privacy i believe