In a situation where you only know a Pardot landing page’s public URL, and you want to open it for editing, here is what you do:
- Go to the landing page in your browser (works for forms, too)
- add the parameter ?PI_DEBUG_ENABLE=1 to the end of the URL. So
https://pardotdomain.yoursite.com/short_url
will become
https://pardotdomain.yoursite.com/short_url?PI_DEBUG_ENABLE=1 - Hit Enter to go to this new URL
- A direct link to the Pardot asset will appear on the upper right of the page. Click it to start editing your page/form right away:

Bookmarklet
You can create a button that does the above work for you, as a bookmarklet:
javascript:(function(){window.open(location.href+"?PI_DEBUG_ENABLE=1","_self");})()
Credits
Credit for this goes to Cheshire Impact’s post on editing live Pardot pages. As far as I can tell, this is a completely undocumented server-side function.