Claude Opus 4.5 vs GPT-5.1-Codex

Compare Claude Opus 4.5 by Anthropic against GPT-5.1-Codex by OpenAI, in 36 community votes, claude opus 4.5 wins 77% of head-to-head duels, tested across 53 shared challenges. Updated February 2026.

In 36 community votes, Claude Opus 4.5 wins 77% of head-to-head duels. Claude Opus 4.5 leads in Web Design, Image Generation. Based on blind community voting from the RIVAL open dataset of 36+ human preference judgments for this pair.