OpenAI Codex
OpenAI's coding agent, bundled into ChatGPT plans instead of sold separately.
Hands-on test: scheduled
| Vendor | OpenAI |
|---|---|
| Free tier | Yes — included with ChatGPT Free (limits not published) |
| Entry paid plan | $8/mo (ChatGPT Go) · $20/mo (Plus) |
| Form | CLI, IDE extension, web, ChatGPT app |
| Platforms | Codex CLI · IDE extension · Web · ChatGPT desktop app (Codex mode) |
| Official site | https://openai.com/codex |
Codex is not sold on its own: it is a feature of ChatGPT plans, from the free plan upward, and it shows up in four places — a terminal CLI, an IDE extension, the web, and a Codex mode inside the ChatGPT desktop app.
The flip side of bundling is opacity: OpenAI does not publish the free plan's Codex usage limits, and the cloud agent (Codex Cloud) is not part of the Free or Go plans. What each plan gets is described in relative terms — the Pro tiers are multiples of Plus — rather than hard quotas.
OpenAI Codex pricing
| Plan | Price | Notes |
|---|---|---|
| ChatGPT Free | $0 | Codex included; limits not published; no Codex Cloud |
| ChatGPT Go | $8/mo | Codex included; no Codex Cloud |
| ChatGPT Plus | $20/mo | |
| ChatGPT Pro | $100/mo | Roughly 5× Plus usage (third-party cross-checked figures) |
| ChatGPT Pro | $200/mo | Roughly 20× Plus usage (third-party cross-checked figures) |
| ChatGPT Business | $20/seat/mo | Annual billing |
Prices read from the official pricing page on October 22, 2026. Vendors in this category change pricing often — check the official page before buying.
Free tier in detail
Included with ChatGPT Free — $0.
- OpenAI's help center states: “Codex is included across ChatGPT plans, including Free and Go”
- Usage limits vary by plan; the free plan's exact limits are not published
- Codex Cloud is not included on the Free and Go plans
No separate sign-up beyond a ChatGPT account.
Features and form
- One subscription covers ChatGPT and the coding agent — no separate tool bill
- Four surfaces: terminal CLI, IDE extension, web, and the ChatGPT desktop app
- The cloud agent (Codex Cloud) starts above the Free and Go plans
Who OpenAI Codex suits
- ChatGPT subscribers who want a coding agent included in the plan they already have
- Terminal-first developers — the CLI is the flagship surface
Our hands-on test
Scheduled — we run every tool through the same frozen benchmark repo and score it with unit tests; results will appear here.
The free plan's unpublished limits may require this benchmark to run in stages.
Pros and cons
Based on published product data (official pricing pages and documentation), not on hands-on use. Hands-on findings will be added here when the benchmark runs complete.
Pros
- Included in ChatGPT plans, including the free plan
- Surface range (CLI, IDE, web, app) matched only by Copilot in this set
- No separate subscription to manage if you already pay for ChatGPT
Cons
- Free-plan usage limits are not published in any official source
- No Codex Cloud on the Free and Go plans
- Usage limits are tied to the ChatGPT plan rather than a dedicated, visible coding quota
Frequently asked questions
Is OpenAI Codex free?
Codex is included with ChatGPT plans, including the free plan — OpenAI's help center states it is “included across ChatGPT plans, including Free and Go”. The free plan's exact usage limits are not published, and Codex Cloud is not included on Free or Go.
How much does Codex cost?
Codex follows your ChatGPT plan: Free $0, Go $8/month, Plus $20/month, Pro at $100 or $200/month (roughly 5× and 20× Plus usage, per third-party cross-checked figures), and Business at $20 per seat/month on annual billing. Figures checked October 22, 2026.
Where can I use Codex?
In a terminal CLI, as an IDE extension, on the web, and in a Codex mode inside the ChatGPT desktop app. The hosted cloud agent, Codex Cloud, starts above the Free and Go plans.
What are Codex's free usage limits?
OpenAI does not publish them. Its help center says limits vary by plan, but no official number exists for the free plan — any site quoting one is estimating.