Claude Code vs OpenAI Codex (2026)

Claude Code

by Anthropic

OpenAI Codex

by OpenAI

Pros

• ✓Available across the terminal, VS Code, JetBrains, Slack, the web, desktop, iOS and Android from one subscription, with GitHub Actions and GitLab CI/CD for runs in CI.
• ✓Works as an MCP client and an MCP server at once. It connects out to external servers over HTTP, SSE, stdio and WebSocket, and the claude mcp serve command exposes Claude Code itself for other applications to connect into.
• ✓Runs on Anthropic's own models, with Fable 5.1, Opus 5.5, Sonnet 5 and Haiku 4.5 selectable, and auto mode lets long tasks run with a classifier reviewing each action instead of a per-step prompt.

Limitations

• –There is no standalone Claude Code plan and no free tier: it shares one usage pool with chats on the Claude subscription, so terminal work draws down the same rolling five-hour and weekly limits.
• –The public GitHub repository holds plugins, the changelog and the issue tracker under a license reading All rights reserved, with use governed by Anthropic's Commercial Terms of Service, so the agent's source code is not published.
• –HIPAA coverage is limited to Enterprise and the API and requires a Business Associate Agreement granted case by case after review, and Claude Team is outside that scope.

Pros

• ✓One agent spans the ChatGPT desktop app, the open-source Codex CLI, IDE extensions for VS Code, Cursor and Windsurf, native Xcode and JetBrains integrations, and Codex cloud on the web and iOS.
• ✓Codex reviews GitHub pull requests and GitLab merge requests on request or automatically, and a GitHub Action, the Codex SDK and codex exec bring it into CI and scripted workflows.
• ✓Parallel tasks in separate worktrees, subagents, Skills, plugins, MCP servers and scheduled tasks let Codex take on longer and repeated work, with GPT-6 Sol and GPT-6 Luna on Plus and above.

Limitations

• –Codex usage is metered against plan limits shared with ChatGPT Work, and the number of messages varies with the model, task size and context, so heavy users on Plus may need credits or a Pro plan.
• –OpenAI removed the Codex MCP server on September 5, 2026, so other assistants can no longer call Codex over MCP, although Codex still connects out to external MCP servers.
• –The Codex documentation covers GitHub and GitLab and does not mention Bitbucket, and Codex run with an API key excludes the cloud features such as GitHub code review and Slack.