Ollama vs OpenAI Codex CLI
Ollama and OpenAI Codex CLI are both terminal AI coding tools. Here's how they line up on the things that actually decide it — price, platform, and what they plug into.
| Ollama | OpenAI Codex CLI | |
|---|---|---|
| Pricing | Free | Free tier |
| Platform | windows, mac, linux | windows, mac, linux |
| Works with | claude | chatgpt |
| In one line | Free, open-source tool for running large language models locally on your own hardware — no internet connection or API key required. | OpenAI's free, open-source terminal coding agent — runs agentic file editing, shell commands, and multi-step tasks powered by o4-mini. |
Which should you pick?
On budget alone, Ollama is the lower-cost entry (free), so it's the safer place to start if you're not ready to pay. They target different setups, so let what you already use break the tie. For the full picture, read the reviews below — the verdict is where the real difference shows up.