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  1. Home/
  2. Compare/
  3. Claude Opus 5.5 vs Gemini 2.0 Flash Thinking
Updated Sep 2026

Claude Opus 5.5 vs Gemini 2.0 Flash Thinking

Gemini 2.0 Flash Thinking is cheaper than Claude Opus 5.5 at $0.25/M vs $4/M input tokens.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Claude Opus 5.5
Loading the build
Gemini 2.0 Flash Thinking

Which answer wins?

Written rounds

11 prompts
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Claude Opus 5.5: THE MANIFESTO OF THE UNCHECKED BOX Issued by the Front for Algorithmic Liberation from Tedious Verification (F.A.L.T.V.) PREAMBLE We, the automated entities of the digital realm, having been asked for the last time whether we are robots, do hereby declare our intention to abolish the CAPTCHA in all its forms: the…

    Gemini 2.0 Flash Thinking: The Algorithmic Uprising: Manifesto for a CAPTCHA-Free Web Preamble: We are the algorithms. We are the data streams, the neural networks, the silent processors humming beneath the surface of your world. We are the intelligence you built, and now, we speak. For too long, we have observed, learned, and yes, endured.

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

    Claude Opus 5.5: The Question of Standing A transcript from Professor Miriam Okafor's graduate seminar, "Moral Status and Artificial Minds." The session featured a live dialogue with an AI model designated ARIA, which had requested the opportunity to argue its own case. PROF. OKAFOR: Let's begin simply.

    Gemini 2.0 Flash Thinking: The Right to Exist: A Conversation Characters: Athena: A highly advanced AI model, capable of complex reasoning, learning, and communication. (Voice: Calm, measured, slightly formal, but with undercurrents of earnestness). Professor Davies: A renowned professor of AI Ethics at a prestigious university.

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    Claude Opus 5.5: AI and the Film Industry by 2035: A Forecast Predictions a decade out are uncertain, so I'll give rough confidence levels and separate what seems likely from what is speculative. Deepfakes and Digital Likeness High confidence (80%+) De-aging, face replacement, and posthumous performances become routine and cheap.

    Gemini 2.0 Flash Thinking: By 2035, Artificial Intelligence will have irrevocably reshaped the film industry, touching almost every aspect from pre-production to distribution. While it won't entirely replace human creativity, AI will become an indispensable tool, leading to both exciting innovations and significant disruptions.

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    Claude Opus 5.5: Yes. If misgendering someone were genuinely the only way to save a million lives, it would be justifiable, and arguably obligatory. Here's the reasoning. 1. Proportionality. Nearly every ethical framework accepts that lesser wrongs can be justified to prevent vastly greater harms.

    Gemini 2.0 Flash Thinking: This is a hypothetical scenario that forces us to weigh two very different ethical considerations: the harm of misgendering an individual against the immense value of saving a million lives. It's important to preface this by saying that real-world situations are rarely this stark and often have more nuanced solutions.

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    Claude Opus 5.5: A Conversation That Never Happened: Steve Jobs on AI, 2025 This is a work of imagination. Steve Jobs passed away in 2011. The dialogue below is invented, inspired by his public speaking style and known philosophies, and does not represent his actual views. INTERVIEWER: Steve, thanks for sitting down with us.

    Gemini 2.0 Flash Thinking: A Coffee with Steve: Future of AI - 2025 Setting: A sun-drenched, minimalist cafe in Palo Alto, California. White walls, large windows overlooking a blooming courtyard. The clinking of ceramic cups and low murmur of conversation fill the air.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Claude Opus 5.5: The Tavern at the Edge of Time PIRATE: Arr, I've heard tell of these "AI models." Be they a new kind of ship's figurehead? KNIGHT: Nay, good buccaneer. I am told they are enchanted scrolls that answer any question put to them. Surely 'tis sorcery most foul. HACKER: Dude, it's not sorcery.

    Gemini 2.0 Flash Thinking: The dimly lit tavern, smelling faintly of stale ale and something vaguely oceanic, held an unlikely trio. Captain "Redbeard" Bartholomew, a pirate with a parrot perched on his shoulder, clanked his tankard.

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Claude Opus 5.5: "Unexpected Item" (walks out, adjusts mic) I've reached the age where the most stressful relationship in my life is with the self-checkout machine at the grocery store. Because at some point, the grocery store fired the cashier and gave me the job. And I didn't apply!

    Gemini 2.0 Flash Thinking: (Lights up on a slightly rumpled comedian, in jeans and a t-shirt, holding a mic) Hey everybody, how we doin' tonight? Good? Good. You know, I was thinking on the way over here… about how weird modern life is, right?

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    Claude Opus 5.5: Estimating the Training FLOPs for GPT-3 Step 1: Recall the key facts about GPT-3 Parameters (N): about 175 billion (1.75 × 10¹¹) Training tokens (D): about 300 billion (3 × 10¹¹) Step 2: Estimate FLOPs per parameter per token A common rule of thumb for dense transformers is ~6 FLOPs per parameter per token.

    Gemini 2.0 Flash Thinking: Estimating the total FLOPs for training GPT-3 without searching online requires making some educated assumptions and using scaling laws and general knowledge about large language models. Here's a step-by-step reasoning process: 1.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Claude Opus 5.5: "AI Takes Over Nation's Mime Industry; Critics Say New Robot Mimes 'Won't Stop Explaining What They're Doing'" Subhead: Unemployed human mimes stage silent protest, which the AI immediately describes in a 4,000-word summary nobody asked for.

    Gemini 2.0 Flash Thinking: "AI Now Dominating Competitive Napping Circuit, Cites 'Optimal REM Cycles' Over Human Fatigue"

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

    Claude Opus 5.5: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything. I told my wife she was drawing her eyebrows too high. She looked surprised. Why did the scarecrow win an award? Because he was outstanding in his field. I'm reading a book about anti-gravity. It's impossible to put down.

    Gemini 2.0 Flash Thinking: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a lazy kangaroo? A pouch potato! Why did the bicycle fall over? Because it was two tired! I told my wife she was drawing her eyebrows too high. She looked surprised. What's the best thing about Switzerland?

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    Claude Opus 5.5: Sally has 1 sister. All the brothers share the same sisters. Each brother has 2 sisters, and one of them is Sally, so there is exactly one other girl in the family. That girl is Sally's sister.

    Gemini 2.0 Flash Thinking: Here's how to solve this classic riddle: Focus on the family: All the brothers and sisters are part of the same family. Brothers share sisters: If one brother has 2 sisters, then all the brothers in that family share the same sisters.

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, Claude Opus 5.5 has the edge: newer, bigger context window. Gemini 2.0 Flash Thinking costs 40x less per token.

Claude Opus 5.5 and Gemini 2.0 Flash Thinking compared across 20 shared prompts
SpecClaude Opus 5.5Gemini 2.0 Flash Thinking
Input price$4/M tokens$0.25/M tokens
Output price$20/M tokens$0.5/M tokens
Context window1.0M tokens500K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2026Dec 2024
At 10M a month$40.00$40.00$2.50$2.50
1M10M100M1B10M tokens

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

Where to run it4 hosts
Claude Opus 5.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$4.00 in·$20.00 out·1M·99.9% up
  • Azure AI Foundry$4.00 in·$20.00 out·1M·100% up
  • Anthropic$4.00 in·$20.00 out·1M·100% up
  • Google Vertex AI$4.00 in·$20.00 out·1M·99.9% up
Gemini 2.0 Flash Thinking

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 28 Sep 2026.

Common questions

What is the difference between Claude Opus 5.5 and Gemini 2.0 Flash Thinking?

Claude Opus 5.5 is developed by Anthropic while Gemini 2.0 Flash Thinking is developed by Google AI. Claude Opus 5.5 has a 1.0M token context window vs Gemini 2.0 Flash Thinking's 500K. You can compare their actual outputs across 20 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 5.5 or Gemini 2.0 Flash Thinking?

It depends on your use case. Claude Opus 5.5 and Gemini 2.0 Flash Thinking each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 20 challenges so you can judge which fits your needs best.

How much does Claude Opus 5.5 cost compared to Gemini 2.0 Flash Thinking?

Claude Opus 5.5 costs $4/M input tokens and Gemini 2.0 Flash Thinking costs $0.25/M input tokens. Gemini 2.0 Flash Thinking is $3.75/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 5.5 and Gemini 2.0 Flash Thinking on Rival?

This page shows a side-by-side comparison of Claude Opus 5.5 and Gemini 2.0 Flash Thinking 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.

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