Claude Code vs Codex CLI: Best Terminal AI Coding Agent in 2026

Claude CodeCodex CLI
arenaElo14201408
humanEval93.195.5
sweBench64.370
mmlu92.388.6
gpqa65.260.8
aime8886
Price in/out ($/M)$15 / $75$9 / $36

Our verdict

Claude Code rides on Opus 4.7: stronger long-horizon agents, 1M context, best-in-class MCP ecosystem. Codex CLI rides on GPT-5.4 Codex: highest HumanEval, tight OpenAI tool-calling, faster loops. Pick Claude Code for multi-hour refactors; pick Codex CLI for fast PR factories.

Claude Code · Codex CLI · All AI model comparisons