[Update Reply]: Hi! thank you for the reply. I have tested your addon, and I am testing many extensions in firefox. I have a 27" screen and I am a graphic designer. Do you think I don't know the latest Upscaling Ai tools what they do? I have tested your addon and it didn't Unblur the images and there are no image thumnails here for demonstration purposes for people to know how to use it this.
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It doesn't do anything and They haven't Updated that addon since 2023. :-(

Should be preinstalled when installing firefox, just like transparent-standalone-image, and Ublock Origin

Essential for any supported browser.

Supports fractional screen scale factors properly. When my screen is scaled to 125% (5/4), it properly enables nearest scaling at 160% page zoom (8/5) or pixel scale factor 8/4, rather than 200%.

Great for looking at pixel art.

Отличное расширение! Купив 4К монитор и выставив масштаб 200% в системе заметил, что множество сайтов не имеют изображений достаточного размера и при масшитабировании они превращаются в черезчур размытые. Это расширение даёт возможность выбора как будут выглядеть мелкие изображения при масштабировании - со ступеньками, но чёткие, или сглаженные и размытые.

I use this to read webtoons at 200% zoom. Great improvement over default.

Great on a 4K display with 200% scale set in Windows 10. Images get sharp just like they were in full HD.

An absolute lifesaver for those of us with 4K displays living in a 1080p world. Eliminates the annoying bilinear filtering that Firefox uses to scale low res images to fit high res screens, making everything look so much sharper and clearer for those of us with more pixels to spare than your average web surfer. Even works on YouTube videos. If you're one of the few that have moved beyond Full HD, then this is a must-have extension until the internet finally catches up with modern screen resolutions and makes high-res images more mainstream.

Increases sharpness of all the pictures in the Internet!!! Well done!!!

Noticed sites like reddit was upscaling wrong. The icons were fuzzy becuase they don't have 'true' HiDPI support. This add-on fixed it by making it a true 4X resolution. Simply upscaled, no "interpolation" or blurryness to it. Perfection!

Running at anything but 96dpi will guarantee getting blurry graphics on many if not most sites. 96dpi produces text that is way too small on Hi-DPI monitors not to mention it is a leftover from the CRT days.

SmartUpscale handles many low resolution graphics on web pages so I can now use Full Page Zoom on many sites.

What I would like to see, if possible, is the ability to set specific sites to use 'Disable blur' not just all sites. Some sites look great with this option, others not so much.

Of course the real solution for blurry graphics is Web Masters using DPI awareness and serve up the right resolution graphics for the users monitor. SVG graphics would also help.