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.

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.

Claude Opus 4.8 vs GPT-5.1-Codex-Mini: Which Is Better?

Updated May 2026

Our Verdict

Claude Opus 4.8

GPT-5.1-Codex-MiniRunner-up

No community votes yet. On paper, Claude Opus 4.8 has the edge — newer, bigger context window.

GPT-5.1-Codex-Mini is 4.2x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.8

Input

$5.00

Output

$25.00

GPT-5.1-Codex-Mini

Input

$1.50

3.3× cheaper

Output

$6.00

4.2× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 3.3× input, 4.2× output

Writing DNA

Style Comparison

Similarity

49%

Claude Opus 4.8 uses 77.6x more emoji

Claude Opus 4.8

GPT-5.1-Codex-Mini

60%Vocabulary65%

19wSentence Length20w

0.46Hedging0.56

4.7Bold3.3

3.2Lists3.4

0.78Emoji0.00

1.15Headings0.08

0.04Transitions0.05

Based on 27 + 13 text responses

Research

What we learned reading every model

Claude Opus 4.8 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

GPT-5.1-Codex-Mini vs MiniMax M3New provider

Claude Opus 4.8 vs Grok 3New provider

Claude Opus 4.8 vs Llama 4 MaverickNew provider

Updated May 2026

Our Verdict

Claude Opus 4.8

GPT-5.1-Codex-MiniRunner-up

No community votes yet. On paper, Claude Opus 4.8 has the edge — newer, bigger context window.

GPT-5.1-Codex-Mini is 4.2x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.8

Input

$5.00

Output

$25.00

GPT-5.1-Codex-Mini

Input

$1.50

3.3× cheaper

Output

$6.00

4.2× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 3.3× input, 4.2× output

Writing DNA

Style Comparison

Similarity

49%

Claude Opus 4.8 uses 77.6x more emoji

Claude Opus 4.8

GPT-5.1-Codex-Mini

60%Vocabulary65%

19wSentence Length20w

0.46Hedging0.56

4.7Bold3.3

3.2Lists3.4

0.78Emoji0.00

1.15Headings0.08

0.04Transitions0.05

Based on 27 + 13 text responses

Research

What we learned reading every model

Claude Opus 4.8 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

GPT-5.1-Codex-Mini vs MiniMax M3New provider

Claude Opus 4.8 vs Grok 3New provider

Claude Opus 4.8 vs Llama 4 MaverickNew provider