Note: Though the edits are temporary and disappears the moment you reload that page. So no need to worry when using this code, as you are not doing anything illegal here.
For Chrome & IE
- Now press Home key, this will take you to the starting point of that code in address bar.
- Right-click on Firefox toolbar and choose New Bookmark. Add the above code manually in the location box of the bookmark and give any name for the bookmark as you wish.
- Add Edit Website – Drag this link to your bookmarks toolbar.
- Once this added to the bookmark toolbar, go to any web page and just click the Edit Website bookmark on toolbar and you should now be able to edit the webpage.
Alternatively, you can use Firefox console, Press Ctrl + Alt + K and paste the code and press Enter.