What is the difference between Claude Opus 4.5 and Claude Sonnet 4?

Both are developed by Anthropic but target different use cases. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.5 or Claude Sonnet 4?

It depends on your use case. Claude Opus 4.5 and Claude Sonnet 4 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 can I compare Claude Opus 4.5 and Claude Sonnet 4 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.5 and Claude Sonnet 4 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 4.5 and Claude Sonnet 4?

Both are developed by Anthropic but target different use cases. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.5 or Claude Sonnet 4?

It depends on your use case. Claude Opus 4.5 and Claude Sonnet 4 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 can I compare Claude Opus 4.5 and Claude Sonnet 4 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.5 and Claude Sonnet 4 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 4.5 vs Claude Sonnet 4: Which Is Better?

Updated Nov 2025

Our Verdict

Claude Opus 4.5

Claude Sonnet 4Runner-up

No community votes yet. On paper, Claude Opus 4.5 has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.5

Input

—

Output

—

Claude Sonnet 4

Input

$3.00

Output

$15.00

Writing DNA

Style Comparison

Similarity

75%

Claude Sonnet 4 uses 6.3x more transitions

Claude Opus 4.5

Claude Sonnet 4

64%Vocabulary62%

55wSentence Length111w

0.86Hedging0.40

5.8Bold5.0

4.5Lists9.3

0.15Emoji0.88

1.59Headings2.16

0.05Transitions0.33

Based on 24 + 17 text responses

Research

What we learned reading every model

Claude Opus 4.5 and Claude Sonnet 4 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 Opus 4.5 vs MiniMax M3New provider

Claude Opus 4.5 vs GPT-5New provider

Claude Opus 4.5 vs Claude Opus 4Same lab

Updated Nov 2025

Our Verdict

Claude Opus 4.5

Claude Sonnet 4Runner-up

No community votes yet. On paper, Claude Opus 4.5 has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.5

Input

—

Output

—

Claude Sonnet 4

Input

$3.00

Output

$15.00

Writing DNA

Style Comparison

Similarity

75%

Claude Sonnet 4 uses 6.3x more transitions

Claude Opus 4.5

Claude Sonnet 4

64%Vocabulary62%

55wSentence Length111w

0.86Hedging0.40

5.8Bold5.0

4.5Lists9.3

0.15Emoji0.88

1.59Headings2.16

0.05Transitions0.33

Based on 24 + 17 text responses

Research

What we learned reading every model

Claude Opus 4.5 and Claude Sonnet 4 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 Opus 4.5 vs MiniMax M3New provider

Claude Opus 4.5 vs GPT-5New provider

Claude Opus 4.5 vs Claude Opus 4Same lab