Codex CLI vs Gemini CLI
Codex CLI and Gemini CLI side by side: what each one is, verified plan pricing and install commands where we have them, and the full review of each.
Codex CLI
OpenAI's open-source (Apache-2.0) terminal coding agent, built in Rust. Included with ChatGPT Plus from $20/mo or usable with an API key. Defaults to GPT-6.1 Sol.
Gemini CLI
Open sourceGoogle's open-source (Apache 2.0) terminal agent for Gemini models. Paid Gemini API, Vertex AI, and Code Assist Standard or Enterprise users keep access; unpaid tier and Google One users moved to Antigravity CLI on June 18, 2026.
At a glance
| Field | | |
|---|---|---|
| Category | AI Coding | AI Coding |
| Website | github.com | github.com |
| Pricing | Plus - $20/mo: Codex in the CLI, IDE extension, web, and iOS, plus cloud code review and Slack; Pro - $100, $200, or $500/mo: everything in Plus with no five-hour limit; Ultrafast mode on Pro $500; Business - $20/user/mo billed annually ($25 monthly), 2+ users; Enterprise and Edu - contact sales; API key - pay per token at OpenAI API rates; no cloud features; Free and Go ($8/mo) - GPT-6 Luna in the desktop app only, subject to rollout | Gemini API key or Vertex AI (pay-as-you-go) - cost based on model and token usage; Gemini Code Assist Standard - $22.80 per user per month, or $19 with an annual commitment; 1,500 requests per user per day; Gemini Code Assist Enterprise - $54 per user per month, or $45 with an annual commitment; 2,000 requests per user per day; Unpaid tier and Google One users - replaced by Antigravity CLI on June 18, 2026, per Google's quota page; Google AI Pro (1,500 requests per day) and Ultra (2,000) - still listed in the same page's quota table, which disagrees with Google's earlier announcement that they moved to Antigravity CLI; confirm before relying on it |
| Install | curl -fsSL https://chatgpt.com/codex/install.sh | sh or npm install -g @openai/codex or brew install --cask codex | npm install -g @google/gemini-cli or brew install gemini-cli or npx @google/gemini-cli |
| Models | GPT-6.1 Sol is the default as of CLI 0.161.0, with GPT-6 Astra, GPT-6 Sol, and GPT-6 Luna also available on ChatGPT plans. API-key sessions get whichever models the key can access, and custom Responses-compatible providers can be configured. | The /model command offers Auto (Gemini 3), which routes between Gemini 3 Pro and Gemini 3 Flash, Auto (Gemini 2.5), which routes between Gemini 2.5 Pro and Flash, or a manual pick. Pass --model to choose at startup. The docs note Gemini CLI has not been optimized for Gemini 4 Argon and point to Antigravity for that model. |
| Last verified | October 17, 2026 | October 17, 2026 |
In Depth
Codex CLI
Codex CLI is OpenAI's coding agent for your own machine. Run `codex` in a repository and it opens a full-screen terminal UI where it reads the code, proposes and applies edits, runs commands inside a sandbox with approval controls, and keeps a resumable session history. It is open source under Apache-2.0 and written in Rust, and the same agent also ships as an IDE extension (VS Code, Cursor, Windsurf), a desktop app (`codex app`), and a scriptable `codex exec` mode for CI. Sign in with ChatGPT to use the usage allowance on a Plus, Pro, Business, Edu, or Enterprise plan, or sign in with an API key and pay standard API rates instead (API-key sessions skip the cloud features such as GitHub code review and Slack). Project instructions live in AGENTS.md, and MCP servers, skills, plugins, and subagents extend what it can do. OpenAI ships CLI releases fast - four landed between October 1 and October 8, 2026 - so the changelog is worth watching. Pick Codex CLI over Codex cloud when local services, your own toolchain, and immediate feedback matter more than async background runs.
Gemini CLI
Gemini CLI is Google's open-source terminal agent for Gemini models. It reads and edits large codebases, runs shell commands, connects MCP servers, takes project instructions from GEMINI.md files, checkpoints long sessions so you can resume them, and runs non-interactively with -p and --output-format json for scripts and CI, with a GitHub Action for pull request reviews and issue triage. The big 2026 change is who it is for. Google's quota and pricing page says unpaid tier and Google One users had Gemini CLI replaced by Antigravity CLI on June 18, 2026, yet the same page's quota table still lists Google AI Pro (1,500 requests per day) and Ultra (2,000), so confirm Pro or Ultra access before relying on it. Organizations on Gemini Code Assist Standard or Enterprise keep full access, and anyone can still run it with a paid Gemini API key or through Vertex AI. The GitHub README still describes the old free tier, so trust the quota page over it. If you are an individual developer who picked Gemini CLI because it was free, read the migration guide and look at Antigravity CLI; if your team already pays for Gemini through Google Cloud, Gemini CLI is still actively shipped, with weekly stable releases.
FAQ
Answers taken from each tool's verified fact sheet, with the date it was last checked.
How much does Codex CLI cost?
As of October 17, 2026: Plus - $20/mo: Codex in the CLI, IDE extension, web, and iOS, plus cloud code review and Slack; Pro - $100, $200, or $500/mo: everything in Plus with no five-hour limit; Ultrafast mode on Pro $500; Business - $20/user/mo billed annually ($25 monthly), 2+ users; Enterprise and Edu - contact sales; API key - pay per token at OpenAI API rates; no cloud features; Free and Go ($8/mo) - GPT-6 Luna in the desktop app only, subject to rollout. Source: openai/codex README, Codex pricing, Codex changelog.
How do I install Codex CLI?
Official install commands as of October 17, 2026: curl -fsSL https://chatgpt.com/codex/install.sh | sh or npm install -g @openai/codex or brew install --cask codex.
Which models does Codex CLI use?
As of October 17, 2026: GPT-6.1 Sol is the default as of CLI 0.161.0, with GPT-6 Astra, GPT-6 Sol, and GPT-6 Luna also available on ChatGPT plans. API-key sessions get whichever models the key can access, and custom Responses-compatible providers can be configured.
How much does Gemini CLI cost?
As of October 17, 2026: Gemini API key or Vertex AI (pay-as-you-go) - cost based on model and token usage; Gemini Code Assist Standard - $22.80 per user per month, or $19 with an annual commitment; 1,500 requests per user per day; Gemini Code Assist Enterprise - $54 per user per month, or $45 with an annual commitment; 2,000 requests per user per day; Unpaid tier and Google One users - replaced by Antigravity CLI on June 18, 2026, per Google's quota page; Google AI Pro (1,500 requests per day) and Ultra (2,000) - still listed in the same page's quota table, which disagrees with Google's earlier announcement that they moved to Antigravity CLI; confirm before relying on it. Source: google-gemini/gemini-cli README, Gemini CLI release notes, Model selection docs, Gemini CLI quota and pricing, Gemini Code Assist pricing, Google: transitioning Gemini CLI to Antigravity CLI.
How do I install Gemini CLI?
Official install commands as of October 17, 2026: npm install -g @google/gemini-cli or brew install gemini-cli or npx @google/gemini-cli.
Which models does Gemini CLI use?
As of October 17, 2026: The /model command offers Auto (Gemini 3), which routes between Gemini 3 Pro and Gemini 3 Flash, Auto (Gemini 2.5), which routes between Gemini 2.5 Pro and Flash, or a manual pick. Pass --model to choose at startup. The docs note Gemini CLI has not been optimized for Gemini 4 Argon and point to Antigravity for that model.
