What is the difference between Claude Opus 4 and Gemini 3.5 Flash?

Claude Opus 4 is developed by Anthropic while Gemini 3.5 Flash is developed by Google AI. Claude Opus 4 has a 200K token context window vs Gemini 3.5 Flash's 1.0M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Gemini 3.5 Flash?

It depends on your use case. Claude Opus 4 and Gemini 3.5 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Gemini 3.5 Flash?

Claude Opus 4 costs $15/M input tokens and Gemini 3.5 Flash costs $1.5/M input tokens. Gemini 3.5 Flash 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 Opus 4 and Gemini 3.5 Flash on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Gemini 3.5 Flash 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 and Gemini 3.5 Flash?

Claude Opus 4 is developed by Anthropic while Gemini 3.5 Flash is developed by Google AI. Claude Opus 4 has a 200K token context window vs Gemini 3.5 Flash's 1.0M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Gemini 3.5 Flash?

It depends on your use case. Claude Opus 4 and Gemini 3.5 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Gemini 3.5 Flash?

Claude Opus 4 costs $15/M input tokens and Gemini 3.5 Flash costs $1.5/M input tokens. Gemini 3.5 Flash 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 Opus 4 and Gemini 3.5 Flash on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Gemini 3.5 Flash 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 vs Gemini 3.5 Flash: Which Is Better?

Updated May 2026

Our Verdict

Claude Opus 4

Gemini 3.5 Flash

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

Gemini 3.5 Flash is 8.3x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4

Input

$15.00

Output

$75.00

Gemini 3.5 Flash

Input

$1.50

10× cheaper

Output

$9.00

8.3× cheaper

Gemini 3.5 Flash is cheaper on both — 10× input, 8.3× output

Writing DNA

Style Comparison

Similarity

47%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Gemini 3.5 Flash

64%Vocabulary59%

62wSentence Length18w

0.52Hedging0.16

4.4Bold4.4

9.1Lists3.0

0.11Emoji0.00

1.87Headings0.89

0.27Transitions0.11

Based on 16 + 27 text responses

Research

What we learned reading every model

Claude Opus 4 and Gemini 3.5 Flash 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 vs MiniMax M3New provider

Claude Opus 4 vs GPT-5New provider

Claude Opus 4 vs Llama 4 MaverickNew provider

Updated May 2026

Our Verdict

Claude Opus 4

Gemini 3.5 Flash

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

Gemini 3.5 Flash is 8.3x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4

Input

$15.00

Output

$75.00

Gemini 3.5 Flash

Input

$1.50

10× cheaper

Output

$9.00

8.3× cheaper

Gemini 3.5 Flash is cheaper on both — 10× input, 8.3× output

Writing DNA

Style Comparison

Similarity

47%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Gemini 3.5 Flash

64%Vocabulary59%

62wSentence Length18w

0.52Hedging0.16

4.4Bold4.4

9.1Lists3.0

0.11Emoji0.00

1.87Headings0.89

0.27Transitions0.11

Based on 16 + 27 text responses

Research

What we learned reading every model

Claude Opus 4 and Gemini 3.5 Flash 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 vs MiniMax M3New provider

Claude Opus 4 vs GPT-5New provider

Claude Opus 4 vs Llama 4 MaverickNew provider