What is the difference between Claude 3 Opus and GPT-5.1-Codex-Mini?

Claude 3 Opus is developed by Anthropic while GPT-5.1-Codex-Mini is developed by OpenAI. Claude 3 Opus has a 200K token context window vs GPT-5.1-Codex-Mini's 400K. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

Which is better, Claude 3 Opus or GPT-5.1-Codex-Mini?

It depends on your use case. Claude 3 Opus and GPT-5.1-Codex-Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

How much does Claude 3 Opus cost compared to GPT-5.1-Codex-Mini?

Claude 3 Opus costs $15/M input tokens and GPT-5.1-Codex-Mini costs $1.5/M input tokens. GPT-5.1-Codex-Mini is $13.50/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 3 Opus and GPT-5.1-Codex-Mini on Rival?

This page shows a side-by-side comparison of Claude 3 Opus 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.

What is the difference between Claude 3 Opus and GPT-5.1-Codex-Mini?

Claude 3 Opus is developed by Anthropic while GPT-5.1-Codex-Mini is developed by OpenAI. Claude 3 Opus has a 200K token context window vs GPT-5.1-Codex-Mini's 400K. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

Which is better, Claude 3 Opus or GPT-5.1-Codex-Mini?

It depends on your use case. Claude 3 Opus and GPT-5.1-Codex-Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

How much does Claude 3 Opus cost compared to GPT-5.1-Codex-Mini?

Claude 3 Opus costs $15/M input tokens and GPT-5.1-Codex-Mini costs $1.5/M input tokens. GPT-5.1-Codex-Mini is $13.50/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 3 Opus and GPT-5.1-Codex-Mini on Rival?

This page shows a side-by-side comparison of Claude 3 Opus 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.

Claude 3 Opus vs GPT-5.1-Codex-Mini: Which Is Better?

Updated Nov 2025

Our Verdict

GPT-5.1-Codex-Mini

Claude 3 OpusRunner-up

No community votes yet. On paper, GPT-5.1-Codex-Mini has the edge — newer, bigger context window.

GPT-5.1-Codex-Mini is 13x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude 3 Opus

Input

$15.00

Output

$75.00

GPT-5.1-Codex-Mini

Input

$1.50

10× cheaper

Output

$6.00

13× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 10× input, 13× output

Writing DNA

Style Comparison

Similarity

58%

GPT-5.1-Codex-Mini uses 332.9x more bold

Claude 3 Opus

GPT-5.1-Codex-Mini

54%Vocabulary65%

14wSentence Length20w

0.48Hedging0.56

0.0Bold3.3

3.0Lists3.4

0.00Emoji0.00

0.00Headings0.08

0.06Transitions0.05

Based on 3 + 13 text responses

Research

What we learned reading every model

Claude 3 Opus and GPT-5.1-Codex-Mini have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

Claude 3 Opus vs Llama 4 MaverickNew provider

Claude 3 Opus vs MiniMax M3New provider

Claude 3 Opus vs Grok 3New provider

Updated Nov 2025

Our Verdict

GPT-5.1-Codex-Mini

Claude 3 OpusRunner-up

No community votes yet. On paper, GPT-5.1-Codex-Mini has the edge — newer, bigger context window.

GPT-5.1-Codex-Mini is 13x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude 3 Opus

Input

$15.00

Output

$75.00

GPT-5.1-Codex-Mini

Input

$1.50

10× cheaper

Output

$6.00

13× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 10× input, 13× output

Writing DNA

Style Comparison

Similarity

58%

GPT-5.1-Codex-Mini uses 332.9x more bold

Claude 3 Opus

GPT-5.1-Codex-Mini

54%Vocabulary65%

14wSentence Length20w

0.48Hedging0.56

0.0Bold3.3

3.0Lists3.4

0.00Emoji0.00

0.00Headings0.08

0.06Transitions0.05

Based on 3 + 13 text responses

Research

What we learned reading every model

Claude 3 Opus and GPT-5.1-Codex-Mini have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

Claude 3 Opus vs Llama 4 MaverickNew provider

Claude 3 Opus vs MiniMax M3New provider

Claude 3 Opus vs Grok 3New provider