debuff vs Phaser
Phaser is the best-known framework for 2D browser games. debuff is a much younger, smaller toolkit built around tuning, testing and working with coding agents. This page compares them on what each actually ships, as of October 2026, and says where Phaser is the better choice.
Short answer
Pick Phaser if you want a mature, full-featured framework with built-in physics, a large community and years of examples, or a visual editor. Pick debuff if you want a small runtime, deterministic tests and fuzzing built in, and a coding agent that can attach to the game you have open.
At a glance
| debuff 0.2 | Phaser 4.2.1 | |
|---|---|---|
| License | MIT | MIT |
| Language | TypeScript | JavaScript, with TypeScript types |
| Maturity | New, early development | Over a decade of releases |
| Physics | Tile collision; no rigid-body engine | Built in (Arcade and Matter) |
| Rendering | WebGL2, Canvas 2D fallback | GPU renderer with filters and lighting (phaser.io/phaser4) |
| Visual editor | None | Phaser Editor, paid ($12/month) |
| Full runtime, brotli | 20 kB (every debuff package) | 276 kB (phaser.min.js) |
| Testing | Deterministic scenarios, screenshot baselines, fuzz | HEADLESS renderer; testing is up to you |
| Coding agents | MCP server for the running game, AGENTS.md in new projects | llms.txt, 28 skills, Editor MCP server |
| Community | Small | Large (about 40k GitHub stars), forums, Discord |
Each library's complete prebuilt bundle (all debuff packages, phaser.min.js), compressed with brotli and measured on 17 October 2026. Tree-shaken games ship less.
Where Phaser is stronger
- Features. Physics engines, a filter and lighting system, tilemaps, cameras, particles and tweens are all built in. debuff has no rigid-body physics.
- Maturity. Phaser has shipped for over a decade. Its API is stable, and v4 stays close to v3, so most v3 material still applies.
- Learning material. Thousands of examples, tutorials and answered questions. When something goes wrong, someone has usually hit it before.
- Editor. Phaser Editor gives you scene editing, if you're happy to pay for it. debuff has no editor.
- Agent docs. Phaser ships skills files in its main repository and an llms.txt, and has an official MCP server for Phaser Editor scenes.
Where debuff is different
- Size. The whole debuff runtime is a fraction of Phaser's bundle, and
debuff buildfails if dev-only code leaks into production. - Determinism and tests. debuff runs on fixed steps with a seeded RNG. Scenarios (JSON scripts with expectations and screenshot captures) run headless with
npm test, andnpx debuff fuzzplays the game with random input and saves every crash or stuck state as a replay. - Agents on the running game. Phaser's MCP server edits scenes in its editor. debuff's MCP server lets an agent attach to the game you have open, read the notes you flag in the overlay, reproduce that moment with
game_replay, and tune typed params in your tab, where you can undo them. The agent comparison post covers this in detail. - Explained errors. A runtime error says whose bug it is (your code, an API misuse, or debuff itself) and points at the source line.
Which to choose
If your game needs physics, lots of built-in systems, or a large community to lean on, use Phaser. If you're making a small game, want tests and fuzzing from day one, or want to work closely with a coding agent, try debuff:
npm create debuff@latest my-gameThe walkthrough with Claude Code shows the full loop.