o3 Mini vs Claude Opus 4

Compare o3 Mini by OpenAI against Claude Opus 4 by Anthropic, context windows of 64K vs 200K, tested across 21 shared challenges. Updated March 2026.

Which is better, o3 Mini or Claude Opus 4?

o3 Mini and Claude Opus 4 are both competitive models. o3 Mini costs $1.1/M input tokens vs $15/M for Claude Opus 4. Context windows: 64K vs 200K tokens. Compare their real outputs side by side below.

Key Differences Between o3 Mini and Claude Opus 4

o3 Mini is made by openai while Claude Opus 4 is from anthropic. o3 Mini has a 64K token context window compared to Claude Opus 4's 200K. On pricing, o3 Mini costs $1.1/M input tokens vs $15/M for Claude Opus 4.

Our Verdict
Claude Opus 4
Claude Opus 4
o3 Mini
o3 MiniRunner-up

No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, newer, bigger context window.

o3 Mini is 17x cheaper per token — worth considering if cost matters.

Slight edge
vs

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