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OpenAI Codex review
8.7/10★★★★★OpenAI's coding agent across ChatGPT, CLI, IDE extension, desktop app and cloud
- Best for
- Developers who want parallel, asynchronous tasks and pull requests back, bundled with ChatGPT
- Price
- Freemium · from $8/month
Free: Quick coding tasks on ChatGPT Free - Platforms
- Web, iOS, VS Code, Terminal, Desktop app
- Made by
- OpenAI, San Francisco, USA · since 2015
What it is
Codex is OpenAI's software-engineering agent. It started as an open-source CLI in 2025 and now also runs in ChatGPT on the web, in a desktop app, an IDE extension and as cloud tasks that produce pull requests. It's included with ChatGPT plans.
Latest: OpenAI launched Codex Security in March 2026; Codex passed 2 million weekly users.
What the AI does
- Cloud agent in sandboxed machines that delivers pull requests
- Open-source Codex CLI
- IDE extension and desktop app with multi-agent management
- Automatic GitHub code review
- Subagents, skills, hooks and MCP
- Codex Security vulnerability agent
Pros and cons
- Top CLI agent on Terminal-Bench 2.0
- Low entry price, with free and $8 tiers
- Many surfaces: web, CLI, IDE, desktop, iOS
- Open-source CLI
- Async cloud tasks add latency for quick edits
- Only OpenAI models
- Free and Go tiers get a lighter model
How it scores
Top Terminal-Bench results and strong value thanks to free and $8 entry tiers.
Feature checklist · 6 of 9
- Autonomous agent mode that edits multiple files (yes)
- Inline code completion as you type (no)
- Choice of AI models from more than one vendor (no)
- Use your own API keys, local models or self-hosted deployment (no)
- Extension for existing IDEs (VS Code or JetBrains) (yes)
- Command-line (terminal) agent (yes)
- Cloud agents that keep working in the background (yes)
- AI code review for pull requests (yes)
- Connects to external tools (MCP, plugins or apps like Slack and Jira) (yes)
Alternatives
See all OpenAI Codex alternatives, ranked →
- GitHub Copilot 8.6/10Developers and teams on GitHub who want AI in the IDE they already use, at the lowest entry price
- Claude Code 8.5/10Engineers who hand off large multi-file tasks and long autonomous runs
- Cursor 8.3/10IDE-first developers who want AI in every keystroke and the freedom to switch models
- Amp 7.7/10Experienced developers and teams running many parallel, long-running agents
OpenAI Codex vs GitHub CopilotOpenAI Codex vs Claude CodeOpenAI Codex vs CursorOpenAI Codex vs AmpOpenAI Codex vs ClineOpenAI Codex vs Devin (Devin Desktop, formerly Windsurf)OpenAI Codex vs JetBrains AI (Junie)OpenAI Codex vs ZedOpenAI Codex vs Replit AgentOpenAI Codex vs Gemini Code AssistOpenAI Codex vs Kiro (Amazon Q Developer)OpenAI Codex vs Tabnine
Sources
▸▸ OpenAI Codex in the news
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