Head to head · Coding · updated Oct 17, 2026
OpenAI Codex vs Gemini CLI
OpenAI Codex scores 97 to Gemini CLI's 96 on public evidence for autonomous coding agent, and they rank #1 and #2 there. Both are free to start. Numbers below are the same public signals the ranking uses, recomputed nightly — nothing here is sponsored.
OpenAI Codex
OpenAI's coding agent, available as an open-source CLI, an IDE extension, and a cloud sandbox in ChatGPT.
+ Cloud mode runs many tasks in parallel sandboxes and opens PRs for each.
− Native Windows support in the CLI arrived late and sandboxing can block legitimate commands.
Gemini CLI
Open-source terminal agent that brings Gemini into your shell for coding and automation tasks.
+ Free tier gives a 1M-token context window and around 1,000 requests per day.
− Less reliable at multi-step edits than Claude Code and quietly falls back to Flash under load.
Side by side
public evidence| OpenAI Codex | Gemini CLI | |
|---|---|---|
| Evidence score / 100 | 97 | 96 |
| GitHub stars | 129,451 | 107,413 |
| Hacker News stories, 30d | 10 | 4 |
| Release-feed mentions, 30d | 0 | 0 |
| Last activity | 0 days ago | 0 days ago |
| Pricing | Free tier · Included with ChatGPT Plus $20/mo and Pro; CLI free with API key | Open source · Free tier with generous daily limits; API billing beyond |
| Platforms | cli, web, vscode-extension, mac, linux | cli, mac, windows, linux |
| Maker | OpenAI |
Which one?
Pick OpenAI Codex if
- you want the stronger public evidence (97 vs 96)
- you need it on vscode-extension, web
Best for ChatGPT subscribers who want background coding tasks.
Pick Gemini CLI if
- you need it on windows
Best for developers who want a free terminal agent.