Gemini CLI vs OpenAI Codex
Two of the most-asked-about agents in the coding space. Here's how they actually stack up.
Gemini CLI
Google's open-source terminal coding agent powered by Gemini 3
Free + $20/mo
Read full review →OpenAI Codex
OpenAI's terminal-based coding agent powered by GPT-5
From $20/mo
Read full review →Side-by-side comparison
| Gemini CLI | OpenAI Codex | |
|---|---|---|
| Tagline | Google's open-source terminal coding agent powered by Gemini 3 | OpenAI's terminal-based coding agent powered by GPT-5 |
| Pricing | Free + $20/mo | From $20/mo |
| Categories | coding, cli, autonomous | coding, cli, autonomous |
| Made by | OpenAI | |
| Launched | 2025-06 | 2025-04 |
| Platforms | macOS, Linux, Windows | macOS, Linux, Windows |
| Status | active | active |
Gemini CLI highlights
- + 1 million token context window for deep codebase understanding
- + Multi-file reads and edits from a single terminal session
- + Shell command execution inside the agent loop
- + Plan mode for reviewing tasks before any file is touched
- + MCP support for custom tools and third-party integrations
OpenAI Codex highlights
- + Multi-file edits across your entire local repository
- + GPT-5 and o-series model selection per session
- + Plan-edit-execute loop with step-by-step approval
- + Suggest, auto, and full-auto safety modes
- + Cloud agent runs via chatgpt.com/codex for async tasks
Frequently Asked Questions
Which is better, Gemini CLI or OpenAI Codex?
Neither is universally better. Gemini CLI (Free + $20/mo) leans into coding, while OpenAI Codex (From $20/mo) is closer to coding. Pick based on which workflow you actually do every day.
What is the price difference between Gemini CLI and OpenAI Codex?
Gemini CLI is free + $20/mo. OpenAI Codex is from $20/mo. See the pricing row in the comparison table.
Can I use Gemini CLI and OpenAI Codex together?
In most cases, yes. They serve overlapping but distinct needs, so running them side by side is common until you decide which fits your workflow.