Cline and OpenAI Codex are both open-source agents that edit your project from plain-English requests. Cline is provider-neutral; Codex is made by OpenAI and signs in with a ChatGPT account.
The short version
| Cline | OpenAI Codex | |
|---|---|---|
| Made by | Cline Bot Inc. | OpenAI |
| Where you work | VS Code and other editors, plus a CLI and desktop app | CLI, IDE extension and cloud service |
| Open source | Yes (Apache 2.0) | Yes |
| AI models | Your choice of provider | OpenAI models |
| Cost | Tool is free for individuals. You pay for model usage | Included with ChatGPT plans, or pay API rates |
| MCP servers | Yes | Yes |
| Project instructions | .clinerules (also reads AGENTS.md) | AGENTS.md |
| Install | VS Code Marketplace, or npm i -g cline | npm install -g @openai/codex |
Check cline.bot/pricing and OpenAI's Codex page for current details.
Key differences
Model freedom. Cline lists Anthropic, OpenAI, Google, OpenRouter, local models and more. Codex is built around OpenAI.
Cost shape. Cline has no subscription for the tool. You pay for model usage with your own keys or Cline credits. Codex ties to a ChatGPT plan (OpenAI lists Plus, Pro, Business, Edu and Enterprise, plus a Free plan whose contents are unclear) or an API key.
Editor experience. Cline's panel shows each proposed edit and asks for approval by default, with Plan and Act modes and checkpoints. Codex is terminal-first, with an IDE extension too.
Shared instructions. Both read AGENTS.md, so one file can serve either tool.
Who should pick what
- You want to switch AI providers or run local models: Cline.
- You already pay for ChatGPT: Codex.
- You like working in an editor panel: Cline.
Our verdict
Cline is the flexible choice; Codex is the natural pick for ChatGPT users. See also Claude Code vs OpenAI Codex.