When comparing Piskel vs Paint.NET, the Slant community recommends Piskel for most people. In the question“What are the best pixel art / sprite editors?” Piskel is ranked 7th while Paint.NET is ranked 9th. The most important reason people chose Piskel is:
WPiskel is HTML5-based so it works in any modern browser.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Works in any browser
WPiskel is HTML5-based so it works in any modern browser.
Pro Animation support
Piskel includes onion skinning, exporting to sprite sheets or gifs, defining frame rate, and present live playback.
Pro Sleek interface
It is also easy on the eyes.
Pro Very simple for beginners
Once you get the hang of it its a very powerful tool
Pro Offline versions available
The downloadable version of Piskel (built with node-webkit) is available for Windows, Linux, and Mac OS X.
Pro Easy to use lighten and darken tool
With the click of a button you can create amazing shading.
Pro Enough tools to be powerful
It has enough tools to be powerful, but not too many to put off beginners.
Pro Open source
Piskel is licensed under Apache License, meaning that the user can use the software for any purpose.
Pro Has a straight foreward tile view mode
... so you can instantly see the result while drawing tiles
Pro Easy to learn and use
Unlike most photo editing software, Paint.NET is simple to learn and easy to use. This means less time is spent learning the in's and out's of Paint.NET and more time on photo editing. For those who only edit photos sporadically and don't have time to invest in learning complicated tools for editing, Paint.Net will suit your needs.
Pro Free software
There is no charge for this software; but donations are welcomed.
Pro Lightweight
Paint.net provides a streamlined but effective core tool set. Support for advanced and niche features is provided through modular plugins, allowing the user to install only what's needed.
Pro Actively developed
The project is active and being continually expanded and refined.
Pro Active and friendly community
The forums are filled with tutorials, as well as people who are friendly and eager to help.
Pro Plugins allow extra functionality
Plugins can be made by anyone in the community, and are offered for download on the forum. They extend the capabilities of Paint.NET to cover most tasks.
Pro HiDPI support
Paint.NET supports fully HiDPI displays, with no scaling problems.
Cons
Con Lacks a true resizing tool
There doesn't seem to be any decent tool in Piskel for an easy stretch or shrink. The only ways possible is resizing the whole image or importing and image and shrinking it from the export tool.
Con No button for undo
Have to use ctrl+Z.
Con Rotation is limited
Rotation is only made in predefined angles. Does not support variable rotations or mouse based rotation. Does not support rotating selected areas, only frames-layers.
Con Shading by hand
Shading can be difficult.
Con Doesn't work well with drawpads
In the online tool you can't draw lines at all, yet using a graphic tablet, being in the offline version controls are pretty chunky and everytime you start drawing a line, the screen flickers black for a short period of time.
Con Only available on Windows
Paint.NET is only available on Windows.
Con No project-based interface
You can only edit a single image at a time in Paint.NET. For example, in other tools you can open 5 or a 100 images at the same time, and stack those windows in all directions.
Furthermore, when you are editing in Paint.NET you can only "view" a single image at a time, even though you can have multiple images open. This limits your zooming ability, as the image will go fullscreen quite quickly, and hide parts of it behind the floating toolbars which can not be embedded anywhere on the screen.