When comparing Spine vs GrafX2, the Slant community recommends GrafX2 for most people. In the question“What are the best 2D animation tools for game development?” GrafX2 is ranked 1st while Spine is ranked 2nd.
Ranked in these QuestionsQuestion Ranking
Pro Integration libraries support most engines
Pro Simplified UI allows for an easy learning curve
No-nonsense workflow allows you to create your artwork in programs much better suited for the task like Illustrator and Inkscape for example, while Spine itself focuses only on the important task of skeletal animation.
Pro Allows for easy use of artwork from third party programs
Spine's developers provide scripts which makes exporting artwork from third party programs much easier to do.
Pro Community-driven feature roadmap
Esoteric Software maintains public Trello boards to help plan and prioritize feature additions.
Pro Funded via Kickstarter
Spine received resounding support from Kickstarter backers, beating its pledge goal by over 5 times.
Pro Supports tileset addition and extraction
Pro Scriptable using Lua
GrafX2 is scriptable using the Lua language, which can be used to automate tasks and add new functionality to it. The script library features advanced color reduction and enhancement tools, palette analysis, and much more.
Pro Very large number of tools and effects
Pro Supports many file formats
GrafX2 supports many file formats, including the popular gif and png, but also importing and exporting from deluxe paint, degas elite, and various other editors using custom formats.
Pro Supports animations
The program has a basic support for animation using frames in newer versions. Graphics can be cloned and copied between frames and changed slightly.
See here how to animate with GrapfX2 https://www.youtube.com/watch?v=Gnq6zBZOqoM
Pro Free, open source, and cross-platform
GrafX2 is totally free to use, copy, and modify. It's available on Windows, Linux, Mac OS X, Haiku, AROS, MorphOS, SkyOS, Syllable, Mint, and a few more systems. Basically anything is supported by the SDL library.
Pro Has a great palette tool
You can create gradients from one color to another, work in either RGB or HSL color space, save and load palettes, sort and organize palettes, and even work on "color cycling" images.
Pro Has a customizable UI with themes support
Theme UI style can easily be changed from settings including buttons and colors.
Pro Palette Color Cycling
GraphX2 being based on older 256 bitmap software has inherited some tricks that modern pixel editors do not have . One of them being the ability to cycle color palette and produce animations and effects with it.
Con Professional Edition is expensive
Essential edition includes nearly all features, but IK Weights and Mesh Animations are not included in the Essential Edition.
Con No integration for some major engines
Spine does not directly support several popular 2D engines, including Construct 2, Clickteam Fusion, and GameMaker Studio. Unreal Engine and CryEngine also have no native modules.
Con Ancient interface
The interface looks and feels like it came out of a 20 year old commodore amiga.