What is the difference between Claude Opus 4.8 and GPT-5.1-Codex-Mini?

Claude Opus 4.8 is developed by Anthropic while GPT-5.1-Codex-Mini is developed by OpenAI. Claude Opus 4.8 has a 1.0M token context window vs GPT-5.1-Codex-Mini's 400K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.8 or GPT-5.1-Codex-Mini?

It depends on your use case. Claude Opus 4.8 and GPT-5.1-Codex-Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Claude Opus 4.8 cost compared to GPT-5.1-Codex-Mini?

Claude Opus 4.8 costs $5/M input tokens and GPT-5.1-Codex-Mini costs $1.5/M input tokens. GPT-5.1-Codex-Mini is $3.50/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Claude Opus 4.8 and GPT-5.1-Codex-Mini on Rival?

This page shows a side-by-side comparison of Claude Opus 4.8 and GPT-5.1-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.

Updated May 2026

Claude Opus 4.8vsGPT-5.1-Codex-Mini

GPT-5.1-Codex-Mini is cheaper than Claude Opus 4.8 at $1.5/M vs $5/M input tokens.

Claude Opus 4.8 and GPT-5.1-Codex-Mini compared across 54 shared prompts
Spec	Claude Opus 4.8	GPT-5.1-Codex-Mini
Input price	$5/M tokens	$1.5/M tokens
Output price	$25/M tokens	$6/M tokens
Context window	1.0M tokens	400K tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	May 2026	Nov 2025