Open source alternatives to Codex
50 open source AI apps to use instead, best rated first.
Top picks
- O

Open WebUI
LaunchSelf-hosted AI platform that connects local and cloud models, extends with Python, and keeps your data under your control.
Self-hosted
- A

AutoGPT
LaunchPlatform for building, deploying, and running AI agents that automate repeatable digital work across research, outreach, content, and support without writing code.
- P

pi
LaunchTerminal-based coding agent with a minimal core, 15+ LLM providers, tree-structured session history, and a TypeScript extension system for building your own workflows.
- A

AFFiNE
LaunchAn open-source, local-first knowledge base that merges structured docs, infinite whiteboards, databases, and AI into a single workspace for teams and creators.
- A

aider
LaunchTerminal-based AI coding tool that lets you edit existing codebases or start new projects using LLMs like Claude, GPT, and DeepSeek.
- A

AppFlowy
LaunchOpen source collaborative workspace combining notes, databases, and AI with full data ownership, offline support, and self-hosting options.
More AI apps
About Codex
Codex
Lightweight coding agent that runs in your terminal
Codex is OpenAI's cloud-based coding agent that runs in a sandboxed environment to write features, fix bugs, and answer codebase questions. It works asynchronously on parallel tasks, reading your GitHub repos and creating pull requests with verifiable changes you can review and merge.
- Made by
- OpenAI
- Category
- AI
- Website
- chatgpt.com/codex



