Using Claude

Claude Code vs Codex: Anthropic's CLI vs OpenAI's Coding Agent (2026)

Comparing Claude Code (Anthropic) and Codex (OpenAI) — supervised local terminal vs async cloud delegation, multi-interface, open source, models, pricing, and which to pick.

🌐 This article was machine-translated and may contain inaccuracies. Refer to the Korean original if in doubt.

"Codex" is OpenAI's coding agent (relaunched in 2025 — not the deprecated 2021 Codex model). It's often compared with Claude Code (Anthropic), and the core difference is one thing — Claude Code is a supervised local terminal workflow, while Codex is a multi-interface tool that adds asynchronous cloud delegation on top of a local CLI.

Claude Code vs Codex at a glance Item Claude Code Codex (OpenAI) Made by Anthropic OpenAI Form Terminal CLI, supervised CLI + cloud + IDE Models Claude (Opus, Sonnet) GPT-5 family Strength Local supervised, multi-file Async cloud delegation CLI open source No Yes (Apache-2.0) Pricing Included in $20 Pro/Max Included in ChatGPT plans Both handle daily work on a ~$20 plan. Benchmark scores vary by source, version, and date, so they're hard to state as fact. As of May 2026.

What is Codex?

OpenAI Codex comes in three forms:

  • Codex CLI — a terminal coding agent. Open source (Apache-2.0).
  • Codex cloud — hand it a task in ChatGPT and an isolated cloud sandbox clones your repo, edits code, runs tests, and presents changes (or a PR). You can delegate and do other work meanwhile.
  • IDE extension — integrated into your editor.

It runs on GPT-5-family models and is included in ChatGPT plans (Free through Pro).

What is Claude Code?

Anthropic's Claude-only terminal CLI agent. It reads and edits files locally but defaults to a supervised flow that asks for approval before writes and commands. 1M context on Opus, with programmable hooks and subagents for fine-grained control. Included in Pro/Max. (See how to use Claude Code.)

Key differences

  • Workflow: Claude Code is a supervised local flow with the developer in the loop. Codex also runs a local CLI but shines at async cloud delegation (give a spec, get a result).
  • Isolation vs control: Codex uses OS-kernel sandboxing for strong boundaries but coarser control; Claude Code uses app-level hooks — weaker boundaries but finer control. → Kernel sandboxing for untrusted external code; hooks for enforcing org coding standards.
  • Ecosystem: already on ChatGPT → Codex; already on Claude → Claude Code.

Which to choose

  • Claude Code — when you want to review each step locally across multi-file, large codebases.
  • Codex — when you throw detailed specs and delegate asynchronously, or do lots of terminal-native work.
  • Both — each is enough for daily work on a ~$20 plan, so many developers run both (~$40/mo combined) and cross-check answers on hard problems.

Curious about Cursor (a GUI editor with multiple models)? See Claude Code vs Cursor.

Disclaimer: The base model versions, interfaces, context, pricing, and benchmark scores for both tools change often. Commonly cited benchmark numbers vary by source, version, and date, so this article doesn't state specific scores as fact (performance is a general tendency). Verify the latest in each official doc (code.claude.com, OpenAI Codex docs). This site is not affiliated with Anthropic or OpenAI.

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