Claude Opus 5.5vsOpenAI Codex Mini

Claude Opus 5.5 is developed by Anthropic while OpenAI Codex Mini is developed by OpenAI. Claude Opus 5.5 has a 1.0M token context window vs OpenAI Codex Mini's 200K. You can compare their actual outputs across 1 challenges on Rival to see how they differ in practice.

It depends on your use case. Claude Opus 5.5 and OpenAI Codex Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 1 challenges so you can judge which fits your needs best.

Claude Opus 5.5 costs $4/M input tokens and OpenAI Codex Mini costs $1.5/M input tokens. OpenAI Codex Mini is $2.50/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of Claude Opus 5.5 and OpenAI Codex Mini across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.