What is the difference between Claude Opus 5 and GPT-5 Codex?

Claude Opus 5 is developed by Anthropic while GPT-5 Codex is developed by OpenAI. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 5 or GPT-5 Codex?

It depends on your use case. Claude Opus 5 and GPT-5 Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare Claude Opus 5 and GPT-5 Codex on Rival?

This page shows a side-by-side comparison of Claude Opus 5 and GPT-5 Codex 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 5 and GPT-5 Codex?

Claude Opus 5 is developed by Anthropic while GPT-5 Codex is developed by OpenAI. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 5 or GPT-5 Codex?

It depends on your use case. Claude Opus 5 and GPT-5 Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare Claude Opus 5 and GPT-5 Codex on Rival?

This page shows a side-by-side comparison of Claude Opus 5 and GPT-5 Codex 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 5 vs GPT-5 Codex: Which Is Better?

Updated Jul 2026

Our Verdict

Claude Opus 5

GPT-5 Codex

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 5

Input

$5.00

Output

$25.00

GPT-5 Codex

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

65%

GPT-5 Codex uses 8.5x more emoji

Claude Opus 5

GPT-5 Codex

54%Vocabulary64%

21wSentence Length17w

0.40Hedging0.38

3.9Bold2.3

1.9Lists3.5

0.02Emoji0.15

0.71Headings0.49

0.05Transitions0.05

Based on 27 + 13 text responses

Research

What we learned reading every model

Claude Opus 5 and GPT-5 Codex 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 Codex vs MiniMax M3New provider

GPT-5 Codex vs Gemini 2.5 Pro Preview 06-05New provider

GPT-5 Codex vs Claude Opus 4Cross-provider

Updated Jul 2026

Our Verdict

Claude Opus 5

GPT-5 Codex

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 5

Input

$5.00

Output

$25.00

GPT-5 Codex

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

65%

GPT-5 Codex uses 8.5x more emoji

Claude Opus 5

GPT-5 Codex

54%Vocabulary64%

21wSentence Length17w

0.40Hedging0.38

3.9Bold2.3

1.9Lists3.5

0.02Emoji0.15

0.71Headings0.49

0.05Transitions0.05

Based on 27 + 13 text responses

Research

What we learned reading every model

Claude Opus 5 and GPT-5 Codex 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 Codex vs MiniMax M3New provider

GPT-5 Codex vs Gemini 2.5 Pro Preview 06-05New provider

GPT-5 Codex vs Claude Opus 4Cross-provider