Gemini 2.5 Flash Preview 05-20 (thinking) vs Claude Opus 4

Compare Gemini 2.5 Flash Preview 05-20 (thinking) by Google AI against Claude Opus 4 by Anthropic, in 12 community votes, claude opus 4 wins 60% of head-to-head duels, context windows of 1.0M vs 200K, tested across 11 shared challenges. Updated April 2026.

Which is better, Gemini 2.5 Flash Preview 05-20 (thinking) or Claude Opus 4?

Claude Opus 4 is the better choice overall, winning 60% of 12 blind community votes on Rival. Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $15/M for Claude Opus 4. Context windows: 1049K vs 200K tokens. Compare their real outputs side by side below.

Key Differences Between Gemini 2.5 Flash Preview 05-20 (thinking) and Claude Opus 4

Gemini 2.5 Flash Preview 05-20 (thinking) is made by google while Claude Opus 4 is from anthropic. Gemini 2.5 Flash Preview 05-20 (thinking) has a 1049K token context window compared to Claude Opus 4's 200K. On pricing, Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $15/M for Claude Opus 4. In community voting, In 12 community votes, Claude Opus 4 wins 60% of head-to-head duels.

In 12 community votes, Claude Opus 4 wins 60% of head-to-head duels. Claude Opus 4 leads in Web Design. Based on blind community voting from the Rival open dataset of 12+ human preference judgments for this pair.

Web Design: Claude Opus 4 wins 67% of votes
Image Generation: Gemini 2.5 Flash Preview 05-20 (thinking) and Claude Opus 4 are tied
Our Verdict
Claude Opus 4
Claude Opus 4Winner
Gemini 2.5 Flash Preview 05-20 (thinking)
Gemini 2.5 Flash Preview 05-20 (thinking)Runner-up

Pick Claude Opus 4. In 12 blind votes, Claude Opus 4 wins 60% of the time. That's not luck.

Claude Opus 4 particularly excels in Web Design. Gemini 2.5 Flash Preview 05-20 (thinking) is 21x cheaper per token — worth considering if cost matters.

Clear winner
Writing DNA

Style Comparison

Similarity
81%

Claude Opus 4 uses 52.1x more hedging

Gemini 2.5 Flash Preview 05-20 (thinking)
Claude Opus 4
70%Vocabulary64%
11wSentence Length62w
0.00Hedging0.52
4.2Bold4.4
7.3Lists9.1
0.00Emoji0.11
0.00Headings1.87
0.00Transitions0.27
Based on 3 + 16 text responses
vs

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Gemini 2.5 Flash Preview 05-20 (thinking)Claude Opus 4

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