We review pricing and features regularly, but check them on the official site before subscribing. How we review.
What is OpenAI Codex?
Codex is OpenAI's coding agent: it works from the terminal, from an editor extension, from the web and from mobile, and it is included in whichever ChatGPT subscription you already have. It can work in the cloud on several tasks in parallel, review pull requests automatically and run code in a sandboxed environment. Its CLI is open source.
Pros
- Included in the ChatGPT subscription you already pay for
- Its CLI is open source and accepts your own API key
- Works in the cloud on several tasks at once
- There is some usage, though limited, even on the free plan
Cons
- Since April 2026 it bills against token credits: hard to predict
- Real heavy usage runs to $100-200 a month per developer
- Limits are shared across terminal, web and editor
What OpenAI Codex is like in practice
Where it stands out
It is built for delegation: you describe a self-contained task, it runs in an isolated environment and hands the work back for review. It works well as a queue of tasks you launch and check later, rather than accompanying you while you code. And it comes with ChatGPT's paid subscriptions.
Where it falls short
It needs the project to be buildable in its environment, which is trivial for standard setups and impossible for ones depending on local services or your machine. And the code it returns compiles and looks correct more often than it is correct: reading the full diff is not optional.
How its pricing works
Included in ChatGPT's paid plans with limits by tier, so if you are already in there is no extra spend. For anyone who is not, paying the subscription just for this compares poorly with dedicated agents. The real economic comparison is almost always which subscription you already have.
Is OpenAI Codex right for you?
Yes, if…
You already pay for ChatGPT and want to get more from it: the agent is included, so you add no second subscription. It works in the cloud on several tasks at once and its CLI is open source.
No, if…
You need predictable spending: since April 2026 it bills against token credits and heavy use runs to $100-200 a month. Limits are also shared across terminal, web and editor.
Frequently asked questions
Is Codex free?
There is limited use on the free ChatGPT plan, and the CLI is free if you connect your own API key and pay for the tokens. For serious use, plans run from $8/month (Go) to $200/month (Pro).
How is it billed?
Since 2 April 2026, usage on Plus, Pro, Business and Enterprise is deducted from token credits rather than per message, which makes spending less predictable.
Codex or Claude Code?
Both are powerful terminal agents. Codex is good value if you already pay for ChatGPT; Claude Code is the benchmark for many developers on long tasks over large repositories.
Compare OpenAI Codex head to head
Pricing, features and limits of OpenAI Codex against its direct rivals.
Where OpenAI Codex appears
Rankings where we have picked this tool.