Best OpenAI Codex alternatives
8 tools developers use instead of OpenAI Codex, ranked by popularity. 7 offer a free plan and 5 are open source. Updated October 2026.
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Open-source, git-aware AI pair programmer that runs in your terminal. Same project as "Aider Chat" elsewhere in this directory, now maintained at Aider-AI/aider.
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Open-source terminal coding agent with a TUI that works with any model provider, including local models, and supports LSP, MCP and custom agents.
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Open-source platform for autonomous coding agents built by All Hands AI, running in a sandboxed Docker environment to fix issues and open pull requests.
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Open-source AI agent from Block, runnable as a desktop app or CLI, connecting to external systems via MCP and now governed by the Agentic AI Foundation.
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Google's open-source terminal coding agent built on Gemini models with a 1M-token context window. Shut down for free consumer accounts June 18, 2026.