Is Codex included in ChatGPT Plus? Yes, at $20 a month

Yes. Codex is included in ChatGPT Plus at $20 a month, as of October 27, 2026. OpenAI's Codex pricing page says Codex comes with the Free, Go, Plus, Pro, Business, Edu and Enterprise plans, so there is no separate Codex subscription.

What changes from plan to plan is how much you can use. Plus gets a limit counted in messages per five-hour period, and OpenAI says weekly limits may also apply.

Which ChatGPT plans include Codex

As of October 27, 2026, the pricing page lists these plans:

So the answer to "is Codex free" is partly yes. Free and Go list GPT-6 Luna at Standard speed in the desktop app, subject to rollout. The page gives no numeric Codex limits for Free or Go, so we can't tell you how much you get on them.

Codex usage limits on Plus

OpenAI gives Plus an estimated range of local messages per five-hour period, by model. The page calls these estimates, not fixed limits.

The wide ranges depend on the task. Local messages and cloud chats draw from the same allowance, and OpenAI says cloud tasks may use more of it than local messages. Code Review usage applies only when Codex runs reviews through GitHub. Reviews run locally or outside GitHub count toward your general limits.

Standard Business seats list the same ranges. Pro plans of $100, $200 or $500 a month currently have no five-hour limit. Enterprise and Edu plans with flexible pricing have no fixed rate limits, while those without it get roughly Plus-level limits per seat for most features.

To see where you stand, read our guide on how to check Codex token usage.

What happens when you hit the limit

Plus and Pro users can buy ChatGPT credits and keep working. Business, Edu and Enterprise workspaces with flexible pricing can buy workspace credits. Credits are quoted per million tokens. For GPT-6.1 Sol, the page lists 50 credits for input, 2.5 for cached input and 250 for output, and says a typical task may use 2 to 15 credits. The page prints no dollar value for a credit.

Using Codex with an API key

You can skip the plan limits and pay per token with an OpenAI API key. The pricing page says this covers Codex in the CLI, SDK or IDE extension, and suits automation in shared environments like CI. You pay at API pricing, and model availability follows the models your key can access.

The catch is that the API key gives no cloud features, such as GitHub code review or Slack. Plans fit people who work in the app daily. An API key fits scripts and pipelines.

For how Codex stacks up against a rival on plans and limits, see Claude Code vs Codex.

What to watch

The pricing page carries no update date. It says GPT-5.5 retires from Codex with ChatGPT sign-in on October 14, 2026, and mentions promotional pricing running at least through November 21, 2026. Check the page before you pick a plan, because limits move.