Claude Opus 4.1 vs GPT-5.1-Codex
Compare Claude Opus 4.1 by Anthropic against GPT-5.1-Codex by OpenAI, in 6 community votes, claude opus 4.1 wins 100% of head-to-head duels, context windows of 200K vs 400K, tested across 52 shared challenges. Updated April 2026.
Which is better, Claude Opus 4.1 or GPT-5.1-Codex?
Claude Opus 4.1 is the better choice overall, winning 100% of 6 blind community votes on Rival. Claude Opus 4.1 costs $15/M input tokens vs $1.25/M for GPT-5.1-Codex. Context windows: 200K vs 400K tokens. Compare their real outputs side by side below.
Key Differences Between Claude Opus 4.1 and GPT-5.1-Codex
Claude Opus 4.1 is made by anthropic while GPT-5.1-Codex is from openai. Claude Opus 4.1 has a 200K token context window compared to GPT-5.1-Codex's 400K. On pricing, Claude Opus 4.1 costs $15/M input tokens vs $1.25/M for GPT-5.1-Codex. In community voting, In 6 community votes, Claude Opus 4.1 wins 100% of head-to-head duels.
In 6 community votes, Claude Opus 4.1 wins 100% of head-to-head duels. Claude Opus 4.1 leads in Reasoning. Based on blind community voting from the Rival open dataset of 6+ human preference judgments for this pair.
Pick Claude Opus 4.1. In 6 blind votes, Claude Opus 4.1 wins 100% of the time. That's not luck.
Claude Opus 4.1 particularly excels in Reasoning. GPT-5.1-Codex is 7.5x cheaper per token — worth considering if cost matters.
Style Comparison
Claude Opus 4.1 uses 38.4x more emoji
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