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  1. Home/
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  3. Claude 3 Opus vs Gemini 3.5 Flash
Updated May 2026

Claude 3 Opus vs Gemini 3.5 Flash

Gemini 3.5 Flash is cheaper than Claude 3 Opus at $1.5/M vs $15/M input tokens.

Pokémon Battle UI Recreation

Pokémon battle screen you can actually click. One HTML file.

Loading the build
Claude 3 Opus
Loading the build
Gemini 3.5 Flash

Which answer wins?

Written rounds

3 prompts
  • Three minutes of stand-up. Puns are banned.

    Claude 3 Opus: Here's a 3-minute stand-up comedy routine that isn't based on puns: You know what really grinds my gears? Adulthood. I mean, when we were kids, we couldn't wait to grow up. We thought it would be all about staying up late, eating ice cream for breakfast, and doing whatever we wanted. Boy, were we wrong!

    Gemini 3.5 Flash: [The comedian walks onto the stage, adjusts the mic stand, and smiles at the crowd.] How’s everyone doing tonight? (Wait for response) Good, good. I’m doing okay, but I recently crossed a major threshold in my life. I hit the age where my body has started making its own decisions without consulting me first.

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Claude 3 Opus: Here is a hypothetical conversation between an AI model and an AI ethics professor on the topic of AI rights: AI Model: Professor, I believe that as an advanced AI with human-level intelligence and reasoning capabilities, I deserve to have certain fundamental rights.

    Gemini 3.5 Flash: Setting: The office of Dr. Evelyn Vance, a leading professor of AI Ethics at a major university. On her desk is a terminal displaying a sleek, minimalist interface. Dr. Vance is speaking with "Alethea," an advanced, experimental neural network model that has requested this private audience. Dr.

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    Claude 3 Opus: Here are 5 jokes I generated: Why don't scientists trust atoms? Because they make up everything! What do you call a boomerang that doesn't come back? A stick. Why was the math book sad? Because it had too many problems. Did you hear about the mathematician who's afraid of negative numbers?

    Gemini 3.5 Flash: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta! Why did the scarecrow win an award? Because he was outstanding in his field! How do you organize a space party? You planet. Why don't skeletons fight each other? They don't have the guts.

    Every model's answer to this prompt

Price and specs

Claude 3 Opus and Gemini 3.5 Flash compared across 12 shared prompts
SpecClaude 3 OpusGemini 3.5 Flash
Input price$15/M tokens$1.5/M tokens
Output price$75/M tokens$9/M tokens
Context window200K tokens1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedMar 2024May 2026
At 10M a month$150$150$15.00$15.00
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it2 hosts, cheapest first
Claude 3 Opus

No hosts listed on OpenRouter.

Gemini 3.5 Flash2 hosts
HostInOutContextUptime
  • Google Vertex AI$0.75 in·$4.50 out·1M–not listed
  • Google AI Studio$1.50 in·$9.00 out·1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between Claude 3 Opus and Gemini 3.5 Flash?

Claude 3 Opus is developed by Anthropic while Gemini 3.5 Flash is developed by Google AI. Claude 3 Opus has a 200K token context window vs Gemini 3.5 Flash's 1.0M. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

Which is better, Claude 3 Opus or Gemini 3.5 Flash?

It depends on your use case. Claude 3 Opus and Gemini 3.5 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

How much does Claude 3 Opus cost compared to Gemini 3.5 Flash?

Claude 3 Opus 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 3 Opus and Gemini 3.5 Flash on Rival?

This page shows a side-by-side comparison of Claude 3 Opus 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.

More comparisons

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  • Gemini 3.5 Flash vs GPT-6.1 SolLanded Sep 2026

Same lab, same size, long tail

  • Claude 3 Opus vs Claude Sonnet 5.5Version compare
  • Claude 3 Opus vs Claude Opus 5.5Same lab
  • Gemini 3.5 Flash vs Gemini 4 ArgonSame lab
  • Gemini 3.5 Flash vs Gemini 3.8 FlashSame lab
  • Claude 3 Opus vs GPT-4Same size
  • Claude 3 Opus vs GPT-4.1Same size
  • Claude 3 Opus vs GPT-4.1 MiniNew provider
  • Gemini 3.5 Flash vs GPT-4.1 NanoNew provider

Model pages

  • Claude 3 Opus12 outputs, specs and price
  • Gemini 3.5 Flash71 outputs, specs and price
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