How to view/delete local storage in Firefox?

To inspect your localStorage items you may type console.log(localStorage); in your javascript console (firebug for example or in new FF versions the shipped js console).

You can use this line of Code to get rid of the browsers localStorage contents. Just execute it in your javascript console:

localStorage.clear();

From Firefox 34 onwards you now have an option for Storage Inspector, which you can enable it from developer tools settings

Once there, you can enable the Storage options under Default Firefox Developer tools

Updated 27-3-16

Firefox 48.0a1 now supports Cookies editing.

Updated 3-4-16

Firefox 48.0a1 now supports localStorage and sessionStorage editing.

Updated 02-08-16

Firefox 48 (stable release) and onward supports editing of all storage types, except IndexedDB

You can delete localStorage items one by one using Firebug (a useful web development extension) or Firefox's developer console.

Firebug Method

1. Open Firebug (click on the tiny bug icon in the lower right)
2. Go to the DOM tab
3. Scroll down to and expand localStorage
4. Right-click the item you wish to delete and press Delete Property

Developer Console Method

You can enter these commands into the console:

localStorage; // click arrow to view object's properties
localStorage.removeItem("foo"); 
localStorage.clear(); // remove all of localStorage's properties

Storage Inspector Method

Firefox now has a built in storage inspector, which you may need to manually enable. See rahilwazir's answer below.

As 'localStorage' is just another object, you can: create, view, and edit it in the 'Console'. Simply enter 'localStorage' as a command and press enter, it'll display a string containing the key-value pairs of localStorage (Tip: Click on that string for formatted output, i.e. to display each key-value pair in each line).