URL Queries for debugging in AEM

“?wcmmode=disabled” this would give you a view similar to what you would get in a publish instance. Of course, you can replace disabled with other WCMmodes.

It turns out there are others. These are the ones I find most useful:

• ?debug=layout: This will give you information about all the components you have on the page.
• ?debugClientLibs=true: Writes out all clientlibs using the individual source files, without aggregation like you would normally get. 

Warning: This can sometimes make your page a LOT slower to render. You can also get similar behavior by changing the settings in the "Adobe Granite HTML Library Manager" OSGi service.

• CTRL+SHIFT+U: Use this with ?debugClientLibs=true to show timing information across the page. How long things take to load, etc.

http://localhost:4502/libs/cq/ui/content/dumplibs.html
Shows you all information around the clientlibs used in your AEM environment.

To view logs directly via url (only works on author mode):
server:port/bin/crxde/logs?tail=2000