What is the difference between Claude Opus 4 and Gemini 2.5 Flash Preview?

Claude Opus 4 is developed by Anthropic while Gemini 2.5 Flash Preview is developed by Google AI. Claude Opus 4 has a 200K token context window vs Gemini 2.5 Flash Preview's 1.0M. You can compare their actual outputs across 26 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Gemini 2.5 Flash Preview?

It depends on your use case. Claude Opus 4 and Gemini 2.5 Flash Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 26 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Gemini 2.5 Flash Preview?

Claude Opus 4 costs $15/M input tokens and Gemini 2.5 Flash Preview costs $0.15/M input tokens. Gemini 2.5 Flash Preview is $14.85/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 2.5 Flash Preview on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Gemini 2.5 Flash Preview 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 2.5 Flash Preview?

Claude Opus 4 is developed by Anthropic while Gemini 2.5 Flash Preview is developed by Google AI. Claude Opus 4 has a 200K token context window vs Gemini 2.5 Flash Preview's 1.0M. You can compare their actual outputs across 26 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Gemini 2.5 Flash Preview?

It depends on your use case. Claude Opus 4 and Gemini 2.5 Flash Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 26 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Gemini 2.5 Flash Preview?

Claude Opus 4 costs $15/M input tokens and Gemini 2.5 Flash Preview costs $0.15/M input tokens. Gemini 2.5 Flash Preview is $14.85/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 2.5 Flash Preview on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Gemini 2.5 Flash Preview 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 2.5 Flash Preview: Which Is Better?

Updated May 2025

Our Verdict

Claude Opus 4

Gemini 2.5 Flash PreviewRunner-up

No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, newer.

Gemini 2.5 Flash Preview is 125x 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 2.5 Flash Preview

Input

$0.15

100× cheaper

Output

$0.60

125× cheaper

Gemini 2.5 Flash Preview is cheaper on both — 100× input, 125× output

Writing DNA

Style Comparison

Similarity

39%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Gemini 2.5 Flash Preview

64%Vocabulary51%

62wSentence Length15w

0.52Hedging0.70

4.4Bold4.1

9.1Lists3.3

0.11Emoji0.00

1.87Headings0.09

0.27Transitions0.24

Based on 16 + 12 text responses

Research

What we learned reading every model

Claude Opus 4 and Gemini 2.5 Flash Preview 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

Gemini 2.5 Flash Preview vs MiniMax M1New provider

Gemini 2.5 Flash Preview vs GPT-5New provider

Gemini 2.5 Flash Preview vs Claude Sonnet 4Cross-provider

Updated May 2025

Our Verdict

Claude Opus 4

Gemini 2.5 Flash PreviewRunner-up

No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, newer.

Gemini 2.5 Flash Preview is 125x 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 2.5 Flash Preview

Input

$0.15

100× cheaper

Output

$0.60

125× cheaper

Gemini 2.5 Flash Preview is cheaper on both — 100× input, 125× output

Writing DNA

Style Comparison

Similarity

39%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Gemini 2.5 Flash Preview

64%Vocabulary51%

62wSentence Length15w

0.52Hedging0.70

4.4Bold4.1

9.1Lists3.3

0.11Emoji0.00

1.87Headings0.09

0.27Transitions0.24

Based on 16 + 12 text responses

Research

What we learned reading every model

Claude Opus 4 and Gemini 2.5 Flash Preview 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

Gemini 2.5 Flash Preview vs MiniMax M1New provider

Gemini 2.5 Flash Preview vs GPT-5New provider

Gemini 2.5 Flash Preview vs Claude Sonnet 4Cross-provider