Claude Opus 4 vs Gemini 3 Flash Preview

Compare Claude Opus 4 by Anthropic against Gemini 3 Flash Preview by Google AI, context windows of 200K vs 1.0M, tested across 35 shared challenges. Updated April 2026.

Which is better, Claude Opus 4 or Gemini 3 Flash Preview?

Claude Opus 4 and Gemini 3 Flash Preview are both competitive models. Claude Opus 4 costs $15/M input tokens vs $0.5/M for Gemini 3 Flash Preview. Context windows: 200K vs 1049K tokens. Compare their real outputs side by side below.

Key Differences Between Claude Opus 4 and Gemini 3 Flash Preview

Claude Opus 4 is made by anthropic while Gemini 3 Flash Preview is from google. Claude Opus 4 has a 200K token context window compared to Gemini 3 Flash Preview's 1049K. On pricing, Claude Opus 4 costs $15/M input tokens vs $0.5/M for Gemini 3 Flash Preview.

Our Verdict
Claude Opus 4
Claude Opus 4
Gemini 3 Flash Preview
Gemini 3 Flash Preview

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

Gemini 3 Flash Preview is 25x cheaper per token — worth considering if cost matters.

Too close to call
Writing DNA

Style Comparison

Similarity
99%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4
Gemini 3 Flash Preview
64%Vocabulary55%
62wSentence Length18w
0.52Hedging0.42
4.4Bold7.1
9.1Lists4.5
0.11Emoji0.00
1.87Headings0.84
0.27Transitions0.07
Based on 16 + 24 text responses
vs

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Claude Opus 4Gemini 3 Flash Preview

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
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