Claude Opus 4.5 vs GPT-5.1

Compare Claude Opus 4.5 by Anthropic against GPT-5.1 by OpenAI, in 6 community votes, claude opus 4.5 wins 100% of head-to-head duels, tested across 52 shared challenges. Updated February 2026.

In 6 community votes, Claude Opus 4.5 wins 100% of head-to-head duels. Claude Opus 4.5 leads in Reasoning. Based on blind community voting from the RIVAL open dataset of 6+ human preference judgments for this pair.

Reasoning: Claude Opus 4.5 wins 100% of votes
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