kitio.aiOpenAI Codex vs REA
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. REA is completely free, while OpenAI Codex is freemium.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Cloud coding tasks
- Codex CLI
- IDE extension
- Desktop app
- Automatic PR review
- Binary and app inspection
- Runtime tracing
- Browser behavior analysis
- One-command agent setup
- RL environment recording
| Feature | OpenAI Codex | REA |
|---|---|---|
| Best for | OpenAI's coding agent in the cloud, CLI, IDE and desktop app | Reverse engineering tools that plug into your coding agent |
| Category | Coding | Coding |
| Pricing model | Freemium | Free |
| Starting price | $8/mo | Free |
| Free plan | Yes | Yes, fully free |
| Made by | OpenAI | REA |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
REA is completely free, while OpenAI Codex is freemium.
Free plan
Cheapest paid plan
Top plan
Free trial
6 plans
Free
Free
- Limited Codex usage
- Via ChatGPT account
Go
$8/mo
- ChatGPT Go plan
- More Codex usage than Free
Plus
$20/mo
- ChatGPT Plus plan
- Codex in CLI, IDE and cloud
Pro
$100/mo
- Starting price; $200 and $500 tiers
- Highest Codex limits
Business
$25/mo
- Per user
- Shared workspace and admin controls
Enterprise
Contact sales
- Enterprise security
- Flexible usage
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
OpenAI Codex
- Included in ChatGPT plans
- Runs many tasks in parallel
- Open-source CLI
- Token-based limits are hard to predict
- Free tier usage is small
REA
- Works through the agent you already use
- One-command install
- Clear worked examples
- Requires Node.js and a coding agent
- Results depend on the agent's reasoning
- Reverse engineering may be restricted by software licenses
Which one should you choose?
Choose OpenAI Codex if you want:
- Included in ChatGPT plans
- Runs many tasks in parallel
- Open-source CLI
Watch out: token-based limits are hard to predict.
Choose REA if you want:
- Works through the agent you already use
- One-command install
- Clear worked examples
Watch out: requires node.js and a coding agent.
OpenAI Codex vs REA FAQ
What is the difference between OpenAI Codex and REA?
OpenAI Codex: OpenAI's coding agent in the cloud, CLI, IDE and desktop app. REA: Reverse engineering tools that plug into your coding agent. Both are coding tools.
Is OpenAI Codex or REA cheaper?
REA is completely free, while OpenAI Codex is freemium.
Do OpenAI Codex and REA have free plans?
OpenAI Codex: Yes. REA: Yes, fully free.
Who makes OpenAI Codex?
OpenAI Codex is made by OpenAI, based in United States.
Who makes REA?
REA is made by REA.
Which should I choose, OpenAI Codex or REA?
Choose OpenAI Codex if you value included in chatgpt plans and runs many tasks in parallel. Choose REA if you value works through the agent you already use and one-command install.