Super useful! really comes in handy when working with hiDPI monitors and small dimension pages.
Suggestion: can you add a one-touch option to turn on and off image-rendering: -moz-crisp-edges; on the magnifyng glass? Sometimes it's better to have the anti-aliasing off when doing pixel matching.

Did not work

Excelente, configurable el tamaño de la lupa y el zoom.

I like that it's simple yet useful. The only thing that I don't like is that there is no option to change the zoom level on the Firefox browser

I really love the idea of this add on. I only gave it 3 stars because it's tough to read while moving the magnifying glass....hard to explain. Would be 5 stars if you could set it to be the page width and you just scrolled up and down with the mouse IE: allowing you to magnify a larger area so you could read say a paragraph at a time before moving the mouse.

Other Functionality as is is flawless thus far...nicely done!

a simple light tool. Im using many years many addons. First time i find the exact tool i needed so much cause it does what it says without complicate setup.
And an idea. If its possible make also a square shape of the tool. Much better for reading i think

Neat!!!

is it possible to have a rectangular shape on the magnifier as I would like to use it to read lines of text? nice app :)
非常好的扩展，建议增加自定义启动快捷键。而不是shiift+alt+z

zooming algorithm like soap :(
pleas add option to view lens content like a Photoshop zoomed image

just what i been looking for. :)

Problem with white non-transparent circle may not be due to extension. I had the same problem with a number of extensions until I was alerted to this Firefox setting:

privacy.resistFingerprinting

Apparently a known bug with this means white boxes can appear for some graphic items if it is not set to false.

Soooo every time I use the extension all I get is a non-transparent white circle ...

Thank you for a really useful add-on that works very well, and which now has the option to select a square magnifying glass. Excellent!

is it possible to have a rectangular shape on the magnifier as I would like to use it to read lines of text? nice app :)