Update (May 20, 2026): Google has replaced Gemini CLI with Antigravity 2.0 — a new CLI + desktop app + SDK powered by Gemini 3.5 Flash. The comparison below still applies to the tool’s capabilities, but the branding and model have changed. See our updated Antigravity 2.0 vs Claude Code vs Codex CLI comparison.

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Terminal-based AI coding agents let you describe what you want and the AI writes, edits, and runs code directly in your project. Three major players dominate this space: Claude Code (Anthropic), Codex CLI (OpenAI), and Gemini CLI (Google). Here’s how they compare.

Quick comparison

	Claude Code	Codex CLI	Gemini CLI
Maker	Anthropic	OpenAI	Google
Model	Claude Sonnet/Opus	GPT-5.4/Mini	Gemini 2.5 Pro/Flash
Price	Pro sub ($20/mo)	Plus sub ($20/mo)	Pro sub ($20/mo)
API option	Yes (pay per token)	Yes (pay per token)	Yes (Vertex AI)
Open source	❌	❌	❌
Sandbox	❌	✅	❌
YOLO mode	--dangerously-skip-permissions	--dangerously-bypass-approvals-and-sandbox	--yolo

All three cost the same with a subscription ($20/month) and all three can also use API keys for pay-per-token billing.

Claude Code

Anthropic’s terminal agent. Uses Claude Sonnet 4.6 (default) or Opus 4.6 (premium). Known for the highest code quality and best understanding of complex codebases.

Install and run

npm install -g @anthropic-ai/claude-code
claude  # Interactive mode
claude -p "Add error handling to all API routes" --print  # One-shot

Strengths

• Best code quality — Claude consistently produces the cleanest, most idiomatic code
• Deep codebase understanding — reads and understands large projects well
• Careful by default — asks for permission before making changes
• JSON output mode — useful for automation: --output-format json

Weaknesses

• Rate limited on Pro — Sonnet sessions last ~44 min per 5-hour window
• No sandbox — runs commands directly on your system
• Slower than Codex — more thoughtful but takes longer per task

Best for

Complex refactoring, architecture decisions, code review. When quality matters more than speed.

For a deeper look, see our Claude Code vs Cursor comparison.

Codex CLI

OpenAI’s terminal agent. Uses GPT-5.4 (full) or GPT-5.1 Mini (fast). The most feature-rich of the three with built-in sandboxing.

Install and run

npm install -g @openai/codex
codex login  # Authenticate with ChatGPT account
codex  # Interactive mode
codex exec "Add unit tests for the auth module"  # One-shot

Strengths

• Sandboxed execution — commands run in a sandbox by default, preventing accidental damage
• Generous rate limits — GPT-5.4 gets ~4 hours per 5-hour window on Plus
• Fast Mini model — GPT-5.1 Mini is 3-5x cheaper from quota, great for quick tasks
• Web search — can search the web for documentation and examples

Weaknesses

• Code quality slightly below Claude — good but not as clean
• OpenAI ecosystem lock-in — only works with OpenAI models
• Newer, less mature — occasional rough edges

Best for

High-volume coding sessions where you need many changes fast. The sandbox makes it safer for automated workflows.

Gemini CLI

Google’s terminal agent. Uses Gemini 2.5 Pro (premium) or 2.5 Flash (fast). The newest of the three, with strong multimodal capabilities.

Install and run

npm install -g @google/gemini-cli
gemini  # Interactive mode (requires auth)
echo "Explain this code" | gemini --yolo -m gemini-2.5-flash  # One-shot

Strengths

• Multimodal — can process images alongside code (screenshots of bugs, UI mockups)
• Long context — handles very large files and codebases
• Flash model — Gemini 2.5 Flash is fast and has a separate quota from Pro
• JSON output — --output-format json for automation

Weaknesses

• Rate limits are strict — Pro quota exhausts in ~30 min of heavy use
• Auth complexity — requires Google Cloud auth or OAuth, not just an API key
• Newer, less polished — the CLI experience isn’t as smooth as Claude or Codex

Best for

Projects involving visual elements (UI work, design implementation). The multimodal capability is unique among terminal tools.

Feature comparison

Feature	Claude Code	Codex CLI	Gemini CLI
File editing	✅	✅	✅
Terminal commands	✅	✅ (sandboxed)	✅
Web search	❌	✅	❌
Image input	❌	❌	✅
Multi-file edits	✅	✅	✅
Git integration	Manual	Manual	Manual
Custom system prompt	Via CLAUDE.md	Via config	Via prompt
Streaming output	✅	✅	✅
JSON output	✅	✅	✅

Rate limits compared

On $20/month subscriptions:

	Claude Code	Codex CLI	Gemini CLI
Premium model	~44 min/5h (Sonnet)	~4h/5h (GPT-5.4)	~30 min/day (Pro)
Fast model	~43 min/5h (Haiku)	~8h/5h (Mini)	~5.7h/day (Flash)
Shared quota?	Yes (all models)	Yes (all models)	No (separate per model)

Codex CLI is the most generous. Claude Code and Gemini CLI hit limits faster. Gemini’s advantage is that Pro and Flash have separate quotas — you can exhaust Pro and still use Flash.

Automation comparison

All three support non-interactive mode for scripting:

# Claude Code
claude --model sonnet --dangerously-skip-permissions \
  --output-format json -p "Fix all TypeScript errors" --print

# Codex CLI
codex exec --dangerously-bypass-approvals-and-sandbox \
  -m gpt-5.1-codex-mini "Fix all TypeScript errors"

# Gemini CLI
echo "Fix all TypeScript errors" | gemini --yolo \
  -m gemini-2.5-flash --output-format json

For automated workflows (CI/CD, batch processing), Codex CLI’s sandbox makes it the safest choice. Claude Code’s JSON output is the most structured.

Which should you pick?

Pick Claude Code if:

• Code quality is your top priority
• You’re doing complex refactoring or architecture work
• You want the most thoughtful, careful AI assistant

Pick Codex CLI if:

• You need the most coding time per day (best rate limits)
• Safety matters (sandboxed execution)
• You want web search integrated

Pick Gemini CLI if:

• You work with visual content (UI, design)
• You need multimodal input
• You want separate Pro/Flash quotas

Use multiple: Many developers use Claude for complex tasks and Codex Mini for quick edits. The subscription cost is the same ($20/mo each), so pick based on your primary use case.

What about open-source alternatives?

OpenCode is the open-source alternative that works with any model — including local models via Ollama. It’s free, model-agnostic, and fully private. The tradeoff is less polish and no built-in sandbox.

For IDE-based alternatives, see our GitHub Copilot vs Cursor comparison and best AI coding tools ranking.

FAQ

Which terminal AI coding tool is best?

Claude Code produces the highest quality code and is best for complex refactoring. Codex CLI has the most generous rate limits and built-in sandboxing, making it best for high-volume daily use. Gemini CLI is best for multimodal work involving screenshots and UI. There’s no single winner — it depends on your priority.

Is Gemini CLI free?

Gemini CLI requires a Google AI subscription ($20/month) or Vertex AI API access (pay per token). There’s no permanently free tier for heavy use. However, Google occasionally offers free credits and the Flash model quota is more generous than the Pro model quota.

Can I use all three?

Yes. Many developers use multiple terminal AI tools. Each costs $20/month with a subscription, or you can use API keys for pay-per-token billing. A common setup is Claude Code for complex tasks, Codex CLI Mini for quick edits, and Gemini CLI for UI-related work.

Related: AI Coding Tools Pricing