What is the difference between Claude Sonnet 4.5 and GPT-5.5?

Claude Sonnet 4.5 is developed by Anthropic while GPT-5.5 is developed by OpenAI. Claude Sonnet 4.5 has a 200K token context window vs GPT-5.5's 1.1M. You can compare their actual outputs across 42 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or GPT-5.5?

It depends on your use case. Claude Sonnet 4.5 and GPT-5.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 42 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to GPT-5.5?

Claude Sonnet 4.5 costs $3/M input tokens and GPT-5.5 costs $5/M input tokens. Claude Sonnet 4.5 is $2.00/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 Sonnet 4.5 and GPT-5.5 on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and GPT-5.5 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 Sonnet 4.5 and GPT-5.5?

Claude Sonnet 4.5 is developed by Anthropic while GPT-5.5 is developed by OpenAI. Claude Sonnet 4.5 has a 200K token context window vs GPT-5.5's 1.1M. You can compare their actual outputs across 42 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or GPT-5.5?

It depends on your use case. Claude Sonnet 4.5 and GPT-5.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 42 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to GPT-5.5?

Claude Sonnet 4.5 costs $3/M input tokens and GPT-5.5 costs $5/M input tokens. Claude Sonnet 4.5 is $2.00/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 Sonnet 4.5 and GPT-5.5 on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and GPT-5.5 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 Sonnet 4.5 vs GPT-5.5: Which Is Better?

Updated Apr 2026

Our Verdict

GPT-5.5

Claude Sonnet 4.5Runner-up

No community votes yet. On paper, GPT-5.5 has the edge — bigger model tier, newer, bigger context window.

Slight edge

API pricing

Cost per 1M tokens

Claude Sonnet 4.5

Input

$3.00

1.7× cheaper

Output

$15.00

2.0× cheaper

GPT-5.5

Input

$5.00

Output

$30.00

Claude Sonnet 4.5 is cheaper on both — 1.7× input, 2.0× output

Writing DNA

Style Comparison

Similarity

68%

Claude Sonnet 4.5 uses 45.2x more emoji

Claude Sonnet 4.5

GPT-5.5

64%Vocabulary58%

94wSentence Length18w

0.48Hedging0.74

4.9Bold2.9

8.0Lists5.1

0.45Emoji0.00

1.91Headings1.68

0.07Transitions0.03

Based on 20 + 26 text responses

Research

What we learned reading every model

Claude Sonnet 4.5 and GPT-5.5 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 Sonnet 4.5 vs MiniMax M3New provider

Claude Sonnet 4.5 vs Gemini 2.5 Pro Preview 06-05New provider

Claude Sonnet 4.5 vs Aurora AlphaNew provider

Updated Apr 2026

Our Verdict

GPT-5.5

Claude Sonnet 4.5Runner-up

No community votes yet. On paper, GPT-5.5 has the edge — bigger model tier, newer, bigger context window.

Slight edge

API pricing

Cost per 1M tokens

Claude Sonnet 4.5

Input

$3.00

1.7× cheaper

Output

$15.00

2.0× cheaper

GPT-5.5

Input

$5.00

Output

$30.00

Claude Sonnet 4.5 is cheaper on both — 1.7× input, 2.0× output

Writing DNA

Style Comparison

Similarity

68%

Claude Sonnet 4.5 uses 45.2x more emoji

Claude Sonnet 4.5

GPT-5.5

64%Vocabulary58%

94wSentence Length18w

0.48Hedging0.74

4.9Bold2.9

8.0Lists5.1

0.45Emoji0.00

1.91Headings1.68

0.07Transitions0.03

Based on 20 + 26 text responses

Research

What we learned reading every model

Claude Sonnet 4.5 and GPT-5.5 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 Sonnet 4.5 vs MiniMax M3New provider

Claude Sonnet 4.5 vs Gemini 2.5 Pro Preview 06-05New provider

Claude Sonnet 4.5 vs Aurora AlphaNew provider