Firefox Cookie Editor
Mozilla Firefox offers no way to manipulate cookies directly in the web browser unlike the Opera web browser which comes with those capabilities. (Update: it is possible to edit cookies in recent versions of Firefox natively. Hit Shift-F2 to open the console and use the cookie list command to list all cookies set by the site you are on. You can then click on edit next to a cookie to alter it).
While cookie editing is probably not something that the majority of users would ever want to dive in,it may be useful to some users, for instance web developers who want to test the cookie setting and handling on websites that they control. It can also be an interesting option for security researchers.
Add N Edit Cookies is a Firefox extension that integrates cookie manipulation in the web browser. A link to the cookie editor is added to the end of the tools menu.
When you click on it a separate window is loaded displaying cookies set in the browser. Since it acts independently from Firefox, you can keep both open and work with both windows at the same time.
The main window lists all cookies known to the browser listed by site address and cookie name. You can use the search at the top to filter for specific cookies.
A click on a cookie displays extensive information including the cookie's content, the path, host and expiration date.
A double-click on a cookie loads the editor that offers options to edit all parameters including the value (content) of the cookie. It is possible to change the name, content, domain, path, connection and expiration date.
Cookie Editor can also be used to delete cookies. This can be done easily by selecting one or multiple cookies that you want to remove and hitting the delete button afterwards.
The third and final option provides you with the means to add cookies. This works similar to editing cookies only that all fields are empty by default and need to be filled by you.Advertisement