Side-by-Side Comparison · 2026

OpenAI Codex CLI vs Gemini CLI: Full Comparison (2026)

OpenAI Codex CLI is openai's open-source terminal coding agent powered by its reasoning models. Gemini CLI is google's open-source terminal coding agent, being replaced by antigravity cli. Use the breakdown below to find the right fit for your needs.

OpenAI Codex CLI

OpenAI

Freemium
vs

Gemini CLI

Google

Freemium
This page presents factual information sourced from publicly available vendor documentation and product pages. AIHub does not endorse either product. The right tool depends on your specific use case, team, and requirements — we recommend evaluating both tools directly before making a decision.

Side-by-Side Overview

Pricing Model
OpenAI Codex CLI: FreemiumGemini CLI: Freemium
API Access
OpenAI Codex CLI: AvailableGemini CLI: Available
Platforms
OpenAI Codex CLI: macOS, Linux, Windows (WSL)Gemini CLI: macOS, Linux, Windows, Terminal, VS Code (via Gemini Code Assist)
Integrations
OpenAI Codex CLI: 5 integrationsGemini CLI: 6 integrations
Vendor
OpenAI Codex CLI: OpenAIGemini CLI: Google
Category
OpenAI Codex CLI: Code AssistanceGemini CLI: Code Assistance
Launch
OpenAI Codex CLI: Apr 16, 2025Gemini CLI: Jun 25, 2025
Models
OpenAI Codex CLI: codex-optimized GPT-5 family, o4-miniGemini CLI: Gemini 3.5 Flash, Gemini 3.5 Pro

About OpenAI Codex CLI

Codex CLI is OpenAI's open-source command-line coding agent that runs in your terminal and edits code, runs commands, and executes tests in a sandbox on your local machine. Powered by OpenAI's codex-optimized reasoning models, it reads your repository, plans multi-step changes, and applies them with approval controls. It complements the cloud-based Codex agent, giving developers a local, scriptable, terminal-native agentic coding workflow.

Designed For

  • Terminal-based coding
  • Multi-file refactoring
  • Test generation and fixing
  • Scripted automation of code tasks
Full OpenAI Codex CLI details

About Gemini CLI

Gemini CLI is Google's open-source command-line AI agent that brings Gemini models directly into the terminal. It can understand codebases, edit files, run shell commands, generate apps, and automate workflows using a ReAct-style agent loop. It ships with a generous free tier via a personal Google account and integrates with MCP servers and Google Search grounding. Status: Google announced on 19 May 2026 that Gemini CLI is being replaced by Antigravity CLI, and press coverage of the announcement reports that Gemini CLI and the Gemini Code Assist extensions would stop serving Google AI Pro, AI Ultra and free individual-tier users on 18 June 2026. Google said Antigravity CLI does not yet have full feature parity. We have not confirmed the June cutoff took effect, so check Google's announcement and the GitHub repository for current status.

Designed For

  • Codebase-wide edits
  • Terminal task automation
  • App scaffolding
  • Debugging
Full Gemini CLI details

Strengths & Limitations

OpenAI Codex CLI

Strengths

  • Open-source (Apache 2.0)
  • Runs locally in the terminal
  • Sandboxed execution with approval modes
  • Included with ChatGPT Plus/Pro/Business plans
  • Scriptable and CI-friendly

Limitations

  • Terminal-first (no rich GUI)
  • Heavy usage can hit plan limits
  • Requires OpenAI account/API
  • Newer than some rivals

Gemini CLI

Strengths

  • Open-source (Apache 2.0)
  • Free tier via Google login (individual access was scheduled to end 18 June 2026)
  • 1M token context
  • Google Search grounding built-in
  • MCP support
  • Non-interactive/scriptable mode

Limitations

  • Being replaced by Antigravity CLI (announced 19 May 2026)
  • Newer than Claude Code/Cursor
  • Gemini-only models
  • Terminal-first UX
  • Occasional agent loop errors

Frequently Asked Questions

What is the difference between OpenAI Codex CLI and Gemini CLI?

OpenAI Codex CLI is openai's open-source terminal coding agent powered by its reasoning models, while Gemini CLI is google's open-source terminal coding agent, being replaced by antigravity cli. OpenAI Codex CLI is designed for Professional developers, Terminal power users; Gemini CLI is designed for Developers in Google ecosystem, Cost-conscious devs (free tier). The right fit depends on your specific requirements.

How do the pricing models compare?

OpenAI Codex CLI is available under a Freemium model. Gemini CLI is available under a Freemium model. OpenAI Codex CLI's entry tier starts at $20/mo. Gemini CLI's entry tier starts at $0. Always verify pricing on each vendor's official website as it may change.

What integrations does each tool support?

OpenAI Codex CLI integrates with GitHub, MCP servers, Terminal tools, ChatGPT sign-in. Gemini CLI integrates with GitHub, Google Search, MCP servers, Gemini Code Assist. Check each vendor's documentation for the full and current list.

How do I choose between OpenAI Codex CLI and Gemini CLI?

Consider your team's technical requirements, budget, existing tooling, and use case before deciding. We recommend signing up for free trials or demos of both tools where available, and consulting each vendor's documentation. AIHub provides this comparison for informational purposes only.