Claude Code vs Codex for game development
Which should you pick?
Pick the tool your plan already covers, then judge it on one small game. The documented differences below decide the rest.
- Claude Code if you pay for a Claude plan. Pro and Max include it, the Free plan does not, and it can test in your own Chrome window.
- Codex if you use ChatGPT on any plan. It has a free start, an open-source command-line tool, a built-in browser in the ChatGPT apps and cloud tasks.
- Both if you like to compare. One instructions file can serve the two tools, as the section on using both explains.
Codex here means OpenAI’s coding agent; the board game shares only the name. Every tool fact on this page is as of September 2026.
How the two compare
They match on the basics and differ on plans, browser testing and where they run. The table lists what each maker’s own documentation says.
| Criterion | Claude Code | Codex |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Where it runs | Terminal, VS Code and JetBrains extensions, desktop app, web at claude.ai/code | Command line, IDE extension for VS Code, Cursor and Windsurf, desktop app, cloud at chatgpt.com/codex |
| Access | Claude subscription or Anthropic Console account | ChatGPT account, or an OpenAI API key |
| Price to start | Pro, $20 a month. Not in the Free plan | Included in Free ($0) and Go ($8 a month) |
| Instructions file | CLAUDE.md, and AGENTS.md when a project has no CLAUDE.md |
AGENTS.md, up to 32 KiB by default |
| Plan first | Plan mode: Shift+Tab, or claude --permission-mode plan |
Plan mode: /plan |
| Browser testing | Chrome integration: needs the Claude in Chrome extension and a direct Anthropic plan, not in WSL | Built-in browser in ChatGPT web and desktop app, not in the CLI or IDE extension |
| Add tools (MCP) | claude mcp add <name> -- <command> |
codex mcp add <name> -- <command> |
| Cloud tasks | Web sessions at claude.ai/code | Tasks that end in a diff or pull request |
| Models | Claude Fable 5.1, Opus 5.5, Sonnet 5.5, Haiku 4.5 | GPT-6 Astra, GPT-6.1 Sol, GPT-6 Luna |
Sources for the table:
- Claude Code: Anthropic’s overview, memory docs, best practices, Chrome guide, MCP docs, product page and plans.
- Codex: OpenAI’s README, CLI docs, AGENTS.md docs, best practices, browser docs, MCP docs, cloud docs and pricing.
Codex’s command-line tool is open source under the Apache-2.0 license. Claude Code’s Chrome integration works with Chrome and Edge, and it detects other Chromium browsers. Codex’s browser cannot automate file uploads, and in the Codex CLI a Playwright MCP server stands in for it.
Use both in one project
Yes, you can. Codex reads AGENTS.md, and Claude Code reads it too when a project has no CLAUDE.md. If you keep a CLAUDE.md, Anthropic’s docs say to import the shared file at the top (memory docs):
@AGENTS.md
Use plan mode for changes to the game loop.Put the stack, the run command, the controls and the asset-path rule in AGENTS.md. Reading AGENTS.md directly needs Claude Code v2.1.277 or later, and the import works either way.
JellyBlob shows the switch in practice. According to its creator, AI wrote all of the code, first with GPT-6 Astra in Codex, then in a remake with Claude Opus 5.5 in Claude Code.
Unity and Godot
Both agents write GDScript and C# like any other code, and both connect to the engines’ editors through MCP servers, using the add commands in the table above.
- Godot. The community godot-mcp server launches the editor, runs the project and reads its debug output. Its README gives
claude mcp add godot -- npx @coding-solo/godot-mcp, and Codex takes the same server withcodex mcp add. - Unity. Unity’s official agent plugin supports both Claude Code and Codex on Unity 6 or later. Unity’s CLI connects Claude Code to a running editor with
unity mcp configure claude, and the community MCP for Unity server works with any MCP client. Unity’s own AI tools also include a gateway that brings Claude or Codex into the editor (Unity).
Our catalog has few games on these engines to compare. Creators name Claude Code on 2 Godot and 1 Unity games, and Codex on 2 and 1.
What the catalog says about each
Data note: as of September 30, 2026 the catalog lists 404 games, and 367 of them are Vibe Jam 2026 entries (jam rules: at least 90% of the code written by AI). Creators name the tools themselves, mostly in the jam submission form. We don’t verify them.
Creators name Claude Code on 169 games and Codex on 73. The next table compares those groups with the full catalog.
| Measure | Claude Code games | Codex games | All 404 listed games |
|---|---|---|---|
| Listed games | 169 | 73 | 404 |
| Use Three.js | 106 (63%) | 52 (71%) | 266 (66%) |
| No engine stated | 33 (20%) | 8 (11%) | 74 (18%) |
| Playable on mobile | 111 (66%) | 43 (59%) | 256 (63%) |
| Online multiplayer | 77 (46%) | 36 (49%) | 173 (43%) |
| Top genre | Action | Action | Action |
The two groups look alike. Most games in each use Three.js and list mobile, and action leads for both tools.
At the top, the jam’s results post names A Game About Capybaras Delivering Food first, and its entry lists Claude Code. Fanto’s Mega-Mart came second and WenWare third, and both entries list Codex. Sunset City - The Dark Tower (Claude Code) placed 8th and Kanso (Codex) 9th.
Creators name both tools on 4 games, among them Tech Bros: Save the World, Draw the Life and Rummy - Ombesh.
Read the counts with care. They show what creators of listed games used; they don’t rank the tools. Browse each group on the Claude Code hub and the Codex hub.
Cost and models, as of September 2026
Claude Code comes with paid Claude plans, and its usage limits are shared with the Claude chat app (Claude Help Center). Codex comes with every ChatGPT plan, and OpenAI counts its usage in local messages per five-hour period (OpenAI pricing).
| Plan | Claude Code | Codex |
|---|---|---|
| Free start | Not included | Included |
| Entry price | Pro, $20 a month | Go, $8 a month, and Plus, $20 a month |
| Higher tiers | Max, from $100 a month | Pro, $100, $200 or $500 a month |
| Pay per token | Console account, at API rates | OpenAI API key |
Anthropic’s model overview lists four current models and suggests starting with Claude Opus 5.5 for most workloads. OpenAI’s Codex models page lists GPT-6 Astra, GPT-6.1 Sol and GPT-6 Luna, and its changelog dates GPT-6.1 Sol to September 29, 2026.
Only 7 of the 238 games that name either tool also name a model version, so this page can’t say which model made which game.
Method and date
We read each maker’s own documentation and pricing pages in September 2026, so every tool fact is as of that month. The tool counts cover the 404 games in the catalog as of September 30, 2026, with the tools their creators listed.
We ran no benchmarks, and this page does not rank the tools by quality. Plans and models change often, so check the linked pages before you pay.
Next: a guide for each agent
- Claude Code game development and Codex game development: a workflow for each agent.
- MCP servers for game development: the servers behind the Unity, Godot and browser setups above.
- Cursor game development: the editor that can host either agent’s extension.
- Make games with ChatGPT and make games with Gemini: the chat and agent routes at OpenAI and Google.
- Best AI for game development and best AI game makers: more tools side by side.
- Hubs: games made with Claude, OpenAI games and the Vibe Jam 2026 archive.
Games to look at
A Game About Capybaras Delivering Food
Drive capybaras around a cozy open world delivering food without toppling the fruit stack.
Claude · Simulation 
Fanto's Mega-Mart
Race through a haunted grocery store at rocket speed, grabbing items as you go.
WenWare
Guess the place and year of a 360-degree historical scene.
Tech Bros: Save the World
Fight off waves as a satirical tech mogul and take down rival billionaire bosses.
Claude · Action 
Sunset City - The Dark Tower
Climb toward the Black Tower while sneaking past guards who watch the city.
Claude · Action
Questions
Is Claude Code or Codex better for game development?
Neither wins on our data. The #1 game of Vibe Jam 2026 lists Claude Code, and #2 and #3 list Codex. Creators name Claude Code on 169 of our 404 listed games and Codex on 73, which shows use, not quality.
Can I use Claude Code and Codex in the same project?
Yes. Codex reads AGENTS.md, and Claude Code reads it too when a project has no CLAUDE.md; if you keep a CLAUDE.md, an @AGENTS.md line in it shares the one file. Our catalog lists 4 games that name both tools.
Which is cheaper for game development?
Codex costs less to start: it is in the Free plan, and Go is $8 a month. Claude Code needs Pro at $20 a month or a Console account, and Codex Plus is also $20. Limits differ by plan, so try one small game before you pay.
Which one can test my game in a browser?
Both. Claude Code connects to Chrome through the Claude in Chrome extension, and Codex has a built-in browser in ChatGPT on the web and in the desktop app. In the Codex CLI, where that browser isn't available, a Playwright MCP server does the job.
Can Claude Code or Codex make Unity or Godot games?
Yes, both write GDScript and C# like any other code, and both connect to the editors through MCP servers. For Godot, the community godot-mcp server lets either agent run the project and read its debug output. For Unity, Unity's official agent plugin supports both, and Unity's CLI connects Claude Code to a Unity 6 editor.