The best free physics editor alternatives for 2D game devs in 2026

Ask any 2D game developer what the most annoying step of shipping a level is, and a lot of them will say the same thing: defining collision shapes for every sprite. Rectangles are easy. But the moment you have a curved character, a jagged platform, a spaceship with wings, or a weapon that isn't a rectangle, you need real polygon collision - and hand-typing vertex arrays is a nightmare.

That's why physics editors exist. And that's why the most popular one - CodeAndWeb's PhysicsEditor - sits behind a paywall that a lot of indie devs, students, and jam participants just don't want to pay.

This post is the honest look at the landscape: what a physics editor actually does, why the paid one dominates, and which free alternatives are worth your time in 2026 - including a browser-based option that most developers don't know exists.

What a physics editor actually does

A physics editor (also called a collision shape editor, hitbox editor, or physics body editor) is a small piece of software that does exactly one job well:

1. You load a sprite image (a PNG of your character, a tile, a projectile).
2. You either draw a collision polygon by hand - placing vertices around the outline - or you auto-trace the boundary from the alpha channel.
3. You export the vertex data in a format your physics engine can load - usually a JSON body definition for Phaser, Matter.js, Rapier, Box2D, Cocos, Godot, or a custom engine.

The output is what your engine uses at runtime to detect collisions. Better polygons mean better gameplay - a character whose hitbox is a lazy rectangle feels floaty and unfair; one whose hitbox actually matches the sprite feels precise.

The whole workflow takes minutes per sprite. The value is in the tool: doing it manually in a text editor is a special kind of misery.

Why the paid one dominates

CodeAndWeb's PhysicsEditor has been around since roughly 2013 and it's genuinely well-built. It runs on Windows, macOS, and Linux, exports to about 15 different engines out of the box, has a solid auto-trace, and integrates with their sprite atlas tool TexturePacker. If you're a full-time game studio with a texture-atlas pipeline and a budget, you buy it and move on.

The base license runs CA$39.99 (a perpetual license with 1 year of updates included - you own it forever, only the free updates are time-boxed), often discounted; a Lifetime Updates bundle costs more. That's genuinely cheap for a professional tool. But it's still a paid desktop app to install, and for the developers this post is really for - solo indies, students, game jam teams, hobbyists on a Chromebook, anyone prototyping - the friction of paying and installing a desktop app for a one-off task is the whole problem. Prices as of publication; check codeandweb.com for current offers.

What to look for in a free alternative

Not all free physics editors are actually usable. The realistic checklist:

• Auto-trace from alpha channel. Hand-placing vertices for 40 sprites is not feasible. Any serious editor needs Moore-neighbor boundary tracing (or equivalent) with a simplification pass - usually Ramer-Douglas-Peucker (RDP) - so you get 8–40 vertices instead of hundreds.
• Vertex editing after auto-trace. Auto-trace is 90% right; the 10% wants dragging.
• Origin/pivot control. Coordinates need to be exported relative to the sprite's pivot, not its top-left corner. Otherwise nothing lines up in your engine.
• Multiple export formats. At minimum: Phaser + Matter.js, Rapier, and raw JSON vertices you can adapt to anything.
• Physics properties - density, friction, restitution baked into the export so bodies behave correctly at load.
• Multiple shapes per sprite for compound bodies (arms + torso + legs; chassis + wheels).
• No install, no signup, no watermark - this is what actually distinguishes "free" from "trial."

The current free options

Here's how the realistic 2026 landscape looks. All prices are for the core physics-editing use case only.

The genuinely free desktop options exist but they're aging (PhysicsBodyEditor's JAR distribution is a rough sell in 2026) or narrow in scope. That's the gap browser-based tools fill.

Why a browser-based physics editor makes sense in 2026

The Canvas API is fast enough. getImageData gives you every pixel's alpha channel. Moore-neighbor boundary tracing is ~50 lines of JavaScript. RDP simplification is another ~30. Rendering polygons and vertex handles is native to Canvas. There's no technical reason a physics editor has to be a native app anymore.

What you gain by putting it in the browser:

• Zero install. Open a URL, load a sprite, get vertex data.
• Cross-platform for real. Same tool on Windows, macOS, Linux, ChromeOS, iPad, Android. The paid desktop editors don't do this.
• Nothing uploaded. FileReader + Canvas run entirely client-side. Your unreleased game art never leaves your device.
• Instant sharing. A URL is the app. Send it to your co-jammer.

What you give up: an atlas-packing pipeline, integration with a paid sprite tool, and about 12 of the 15 export formats that CodeAndWeb ship (most of which nobody uses). If you're already deep in a TexturePacker workflow, the paid tool still makes sense. If you're not, you don't need it.

The browser workflow, end to end

Using Physics Editor on 712tools - the free browser-based option in the table above - for a single sprite:

1. Click Sprites and add your PNG (or drag it in). You can load 10 at once and switch between them.
2. Click Wand and hit Auto-Trace. In under a second you get a polygon around the sprite's silhouette. Adjust the Alpha Threshold and Simplify sliders if the fit isn't tight enough.
3. Switch to Edit mode and drag any vertex to fine-tune. Add a second shape for a sensor zone if you need one.
4. Click Settings to set density, friction, and restitution, and pick your export format - Phaser + Rapier, Phaser + Matter.js, or Raw Vertices.
5. Click Export → Copy for clipboard, or Download for a JSON file.

Paste the JSON into your project. That's the whole loop. Ten sprites in fifteen minutes, no install, no login, no cost.

Which engines this actually plugs into

The three built-in export formats cover most 2D game stacks people ship in 2026:

• Phaser + Rapier - the newer, faster physics backend for Phaser 3 / Phaser 4. The export is a polygon with density, friction, restitution baked in.
• Phaser + Matter.js - the classic Phaser physics backend. Export is a fromVertices body with a fixtures array.
• Raw Vertices JSON - plain arrays of [x, y] coordinates offset to the sprite's origin. From here it's a five-line adapter to Box2D, Cocos2d-x, Cocos Creator, Godot (as a CollisionPolygon2D polygon property), LibGDX, PlayCanvas, or Defold.

If your engine wants a slightly different shape (nested objects vs flat arrays, x/y as separate keys vs a tuple), the Raw Vertices output is a two-minute map away from whatever your loader expects.

When you should still pay for PhysicsEditor

To be fair to CodeAndWeb: if any of these apply, buying PhysicsEditor is genuinely the right call.

• You already use TexturePacker and want the atlas + physics workflow in one tool.
• You need one of the more exotic export formats (Chipmunk, Nape, gideros, etc.).
• You're a studio, not a solo dev, and CA$40 per seat is nothing next to the time saved on tooling.
• You want a native desktop app you can drive from the command line as part of a build pipeline.

For everyone else - students, jammers, indies, side-project folks, anyone learning Phaser or Matter.js on a laptop that doesn't need another install - a free browser-based option is the modern answer.

The other tools that pair with a physics editor

Building a 2D game usually means a handful of small utilities alongside the actual engine. The ones that pair naturally with a collision-shape workflow:

• Image Compressor - get your sprite PNGs under 200KB before you ship. Big spritesheets kill mobile web games.
• Image Resizer - resize source art down to the actual game resolution before you trace collisions. Tracing a 4K sprite for a 512px game body is wasted CPU.
• Aspect Ratio Calculator - for laying out UI panels, HUD elements, and cutscene frames.
• JSON Formatter - because you'll be pasting exported body definitions into config files, and one missing brace ruins everything.

All browser-based, all free, all no-signup. Same category of tool as the physics editor itself.

The takeaway

Paid physics editors were the right answer for a long time because the tech to do it in a browser genuinely wasn't there. In 2026 it is. If you're a solo developer, a student, a game jam participant, or you just don't want to install another desktop app to define twenty polygons, use Physics Editor - free, browser-based, private, and it does the whole job.

If you outgrow it and end up buying PhysicsEditor a year from now because you scaled into a full studio pipeline: also fine. Different tools for different stages. But you shouldn't have to pay $30 to learn Phaser.