OpenAI Codex

FreemiumAI Coding & Dev Tools

OpenAI's agentic coding tool, now on gpt-5.3-codex.

Bq By Benchquill Editorial Team ·Updated July 30, 2026 ·How we rate

OpenAI Codex is OpenAI's agentic coding tool (CLI, IDE extension and cloud) now running gpt-5.3-codex, which replaced gpt-5.2-codex in January 2026. It plans, edits and runs code across your repo with sandboxed execution. Access is bundled into ChatGPT plans (Plus $20; Pro tiers at $100 and $200/mo as of April 2026) or via the API (gpt-5.3-codex ~$1.75/1M input, ~$14/1M output). Verify current limits.

Key features

  • Free open-source Codex CLI (npm/brew install)
  • Cloud agents that run tasks in parallel sandboxes
  • IDE extension plus CLI and ChatGPT web integration
  • GPT-5-series Codex models tuned for software engineering
  • Token-based credit usage tied to ChatGPT plan or API key

Pros & cons

Pros

  • CLI is free software; bundled into existing ChatGPT subscriptions
  • Strong parallel cloud-agent capabilities
  • Top SWE-bench-class performance with GPT-5 Codex models

Cons

  • 2026 move to token-based credits makes usage harder to predict
  • Heavy or parallel agent use can consume credits quickly

OpenAI Codex pricing

OpenAI Codex uses a freemium pricing model, with paid plans from Included in ChatGPT: Free, Go $8/mo, Plus $20/mo, Pro from $100/mo; or pay-as-you-go API. A free tier lets you test it before committing. Browse all freemium AI tools we track.

Who should use OpenAI Codex?

OpenAI Codex is best suited for developers in the OpenAI/ChatGPT ecosystem who want a CLI plus cloud agents for autonomous coding. It earns its place for cLI is free software; bundled into existing ChatGPT subscriptions. The main trade-off: 2026 move to token-based credits makes usage harder to predict.

Comparing options? See our best ai coding & dev tools guide, or browse every ai coding & dev tool tracked on Benchquill.

Key concepts behind ai coding & dev tools: AI agent · Function / tool calling · Context window · Open weights · MCP (Model Context Protocol).

OpenAI Codex FAQ

Is OpenAI Codex free?

OpenAI Codex is freemium. Pricing starts at Included in ChatGPT: Free, Go $8/mo, Plus $20/mo, Pro from $100/mo; or pay-as-you-go API.

What is OpenAI Codex best for?

OpenAI Codex is best for developers in the OpenAI/ChatGPT ecosystem who want a CLI plus cloud agents for autonomous coding. Its standout strength: cLI is free software; bundled into existing ChatGPT subscriptions.

What are the best OpenAI Codex alternatives?

The closest alternatives are Claude Code and Cursor. Claude Code is anthropic's terminal-native agentic coding tool, while Cursor is the AI-first code editor built for pair-programming with agents.

AI models behind OpenAI Codex

Related models on our leaderboard: GPT-5.6 Sol, GPT-5.5, GPT-5.6 Terra, GPT-5.4.

OpenAI Codex alternatives

Other top ai coding & dev tools worth comparing.

All 17 alternatives →

Claude Code

AI Coding & Dev Tools
Freemium

Anthropic's terminal-native agentic coding tool.

100
Best for: Developers who want a powerful terminal agent for heavy refactors, codebase exploration and autonomous tasks.

Cursor

AI Coding & Dev Tools
Freemium

The AI-first code editor built for pair-programming with agents.

100
Best for: Developers who want a single, polished AI-native IDE for daily coding plus agentic multi-file work.

GitHub Copilot

AI Coding & Dev Tools
Freemium

The AI pair programmer built into the tools developers already use.

100
Best for: Developers already in the GitHub/VS Code ecosystem who want affordable, deeply integrated AI assistance.

Bolt.new

AI Coding & Dev Tools
Freemium

Prompt, run, edit and deploy full-stack web apps in the browser.

75
Best for: Builders who want to spin up and deploy full-stack web apps and prototypes entirely in the browser.