EditURL

This extension allows you to edit GET parameters on any page.
It automatically decodes and encodes GET parameters for you.

For example url http://example.com/calc?set_var=x%3D3&expression=x%2B2#result
can be edited as:

location:
http://example.com/calc

?parameters:
set_vat = x=3
expression = x+2

#hash:
result