When comparing Piskel vs Pixly, the Slant community recommends Piskel for most people. In the question“What are the best pixel art / sprite editors?” Piskel is ranked 7th while Pixly is ranked 14th. 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 Color selector with different color systems
RGB, CMY, HSB, and a somewhat different HUSL.
Pro Offers color ramp generator
Pixly offers a color ramp generator that then exports directly into a custom palette.
Pro You can use reference images
You can work with a reference image on top of your art, or by its side.
Pro Allows you to continue your work even when not in front of your PC
This tool works on both phones and tablets that run Android, which is handy for when you do not have access to a PC.
Pro Layered projects
Pro Gestures that feel natural on touch screens
In Pixly, you can move the art around with two fingers (like in Google Maps) and change the brush/eraser size with a three-finger pinch.
Pro Supports onion skinning
Onion skinning is also called ghosting. It allows the user to see the past and previous frames, while editing the current frame. This way, the user can make decisions on how to create or change an image.
Pro Mirroring support
In Pixly, the user can make symmetrical art with a mirror, or even go bananas setting up two or more mirrors at different angles at once.
Pro Transparency support
The user can make transparent sprites in Pixly.
Pro Animation support
Even though this is a mobile tool, it's fully featured and even allows you to create animations.
Pro Standard and custom palettes
Pro Live image tiling
The user can create tiles in Pixly and keep an eye on progress in real time.
Pro Color filters
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 No PC version
The PC version has not yet been released.