Head-to-head comparison
OpenAI CodexvsDevin
Two cloud-based autonomous coding agents that finish entire tickets while you do other work. Codex (2026) is OpenAI's GPT-5.6-powered offering, bundled with ChatGPT Pro. Devin is Cognition's pioneer, $500/mo on its own.
At a glance
| OpenAI Codex | Devin | |
|---|---|---|
| Category | Coding | Coding |
| Function | Coding agent | AI engineer |
| Pricing | Paid | Paid |
| Starting price | Bundled with ChatGPT Pro ($200/mo) | Core $20/mo (limited ACUs), Teams $500/mo |
| Editor rating | 4.7 / 5 | 4.2 / 5 |
| Released | May 2026 | March 2024 |
OpenAI Codex
Pros
- Genuinely autonomous on well-scoped tasks
- Parallel task execution (5x usage growth in 2026)
- Bundled with existing ChatGPT Pro
Cons
- Tied to ChatGPT Pro pricing
- Cloud-only — no local agent option
- Reliability still under 70% on multi-file refactors
Devin
Pros
- Genuinely autonomous — no babysitting on good tasks
- Best-in-class for well-scoped tickets
- The Slack integration changes the workflow
Cons
- Expensive vs Cursor/Claude Code
- Still confuses itself on complex tickets
- ACU pricing is hard to predict
Which one should you pick?
Pick OpenAI Codex if
You already pay for ChatGPT Pro ($200/mo) and want autonomous coding bundled. Codex inherits GPT-5.6's reasoning and the broader ChatGPT ecosystem.
See OpenAI Codex details →Pick Devin if
You want the most mature background-agent product. Devin has been doing autonomous engineering longer than anyone and still leads on tougher multi-step tickets.
See Devin details →Bottom line
Codex for the better bundle. Devin for the more mature autonomous product. If you can only justify one, lean Codex (you get ChatGPT Pro out of it too).