OpenAI Codex CLI vs Devin — Which AI Agent Is Better?
An in-depth comparison of OpenAI Codex CLI and Devin across output quality, autonomy, reliability, speed, value, and ease of use. Vote for your favorite.
An in-depth comparison of OpenAI Codex CLI and Devin across output quality, autonomy, reliability, speed, value, and ease of use. Vote for your favorite.
Pick a winner in each category — you can change your vote anytime.
CodexDevinChoose OpenAI Codex CLI if you are chatGPT subscribers who want a capable terminal agent at no extra cost. Choose Devin if you are teams that want to delegate well-scoped engineering tickets end-to-end.
In our editorial scoring, OpenAI Codex CLI leads in 4 of six categories (output quality, reliability, speed and value), while Devin leads in 2 (autonomy and ease of use). On price, OpenAI Codex CLI runs included with chatgpt plans / api and is open source; Devin runs $20/mo entry + usage (acus) and is proprietary.
Codex CLI is OpenAI's open-source coding agent for the terminal. It edits files, runs commands in a sandbox with configurable approval modes, and can hand longer tasks off to Codex cloud to run in the background. Usage is included with ChatGPT Plus/Pro plans, making it the default choice for developers already in the OpenAI ecosystem.
Devin is Cognition's fully autonomous software engineer: give it a task in Slack, Linear, or the web IDE and it plans, writes code, runs tests, and opens a pull request in its own cloud sandbox — including several sessions in parallel. It shines on well-scoped, repetitive engineering work (migrations, test coverage, small features) and improved markedly through its 2.x releases, but it remains weaker on ambiguous, novel tasks, and ACU-based usage pricing means heavy use costs real money. Cognition also acquired Windsurf in 2025, folding its IDE technology into the same product family.
Both work with any OpenAI-compatible provider. Point the base URL at Standard Compute and get unlimited frontier-model compute from $9/mo flat — no per-token billing, no 429 rate limits.
Whichever AI agent you choose, Standard Compute gives you unlimited LLM compute at one flat monthly price. No rate limits, no per-token billing.
