OpenAI Codex review

Codex is OpenAI's coding agent, and it comes with ChatGPT plans rather than as a separate product. The Free and Go tiers, at $0 and $8 a month, are listed for the desktop app with the GPT-6 Luna model. For this list's angle, the relevant tier is Plus at $20 a month, which adds Codex on the web, in the CLI, in the IDE extension and on iOS, plus cloud features such as automatic code review and Slack integration, with GPT-6.1 Sol and GPT-6 Luna. Pro plans run at $100, $200 or $500 a month for higher limits. Teams that automate in CI can instead sign in with an API key and pay API rates, though cloud features such as GitHub review are not available that way. One detail to plan for is that Codex shares usage with ChatGPT Work, so heavy chat use and heavy coding compete for the same allowance.

Who it is for

ChatGPT subscribers who want a coding agent in their editor and cloud code review without another subscription.

Price

Free plan; Go from $8 a month (desktop app), IDE extension listed from Plus at $20 a month.

Go Use Codex for lightweight coding tasks. $8 /month Get Go
Quoted from the vendor pricing page on November 6, 2026.

Key features

• Codex on the web, in the CLI, in the IDE extension and on iOS from the Plus plan
• Cloud integrations such as automatic code review and a Slack integration on Plus
• GPT-6.1 Sol and GPT-6 Luna models on Plus
• Pro plans at $100, $200 or $500 a month for heavier use
• API key option for the CLI, SDK and IDE extension, billed at API rates

Strengths and weaknesses

• Strength: Included with ChatGPT plans many developers already pay for
• Strength: Automatic GitHub code review on Plus and above
• Strength: API key mode suits CI and shared environments
• Weakness: The Free and Go plans are listed for the desktop app only
• Weakness: The IDE extension and cloud features start at Plus, $20 a month
• Weakness: Usage is shared with ChatGPT Work, so heavy chat use reduces coding capacity

Key facts

• Free plan: Yes, quick coding tasks in the desktop app
• Paid plans: Go $8, Plus $20, Pro from $100 a month
• Surfaces: Web, CLI, IDE extension, desktop app, iOS

Where it ranks

OpenAI Codex is No. 5 in our Best AI Coding Assistants verdict.