OpenAI Codex review

Codex makes the most sense for the many developers who already have a ChatGPT subscription. OpenAI sells it inside ChatGPT plans: Free and Go at $8 per month run GPT-6 Luna at standard speed in the desktop app, subject to rollout, while Plus at $20 per month opens Codex on the web, in the CLI, in the IDE extension and on iOS, with GPT-6.1 Sol, automatic code review and a Slack integration. Pro comes in $100, $200 and $500 monthly sizes, and the top size adds an ultrafast mode. Teams can also run Codex with an API key for CI jobs, though that path drops the cloud features such as GitHub review. The main limit is that Codex shares its usage pool with ChatGPT Work, so heavy chat users and heavy coders on one account compete for the same allowance. For a developer who wants agent help and chat on one bill, it is good value.

Who it is for

Developers who already pay for ChatGPT and want a coding agent and automatic code review on the same bill.

Price

Free plan; Go $8 per month; Plus $20 per month; Pro at $100, $200 or $500 per month.

Use Codex for lightweight coding tasks. $8 /month
Quoted from the vendor pricing page on November 9, 2026.

Key features

• Codex on the web, in the CLI, in the IDE extension and on iOS with Plus
• Automatic code review and Slack integration on Plus
• GPT-6.1 Sol and GPT-6 Luna models on Plus
• Usage extends with ChatGPT credits when limits run out
• API key option for CI and other shared environments

Strengths and weaknesses

• Strength: Comes with ChatGPT, so many developers already have access
• Strength: Go at $8 per month is one of the cheapest paid entries
• Strength: Pro is sold in three sizes, so heavy users can scale up
• Weakness: Free and Go are limited to GPT-6 Luna in the desktop app
• Weakness: Cloud features such as GitHub code review need Plus or higher
• Weakness: Codex shares usage limits with ChatGPT Work

Key facts

• Free plan: Yes, GPT-6 Luna in the desktop app
• Paid tiers: Go, Plus, Pro
• Pro sizes: $100, $200 or $500 per month

Where it ranks

OpenAI Codex is No. 3 in our Best AI Coding Assistants verdict.