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  1. Home/
  2. Compare/
  3. Claude Opus 4 vs GPT-5.1 Chat
Updated Nov 2025

Claude Opus 4 vs GPT-5.1 Chat

GPT-5.1 Chat is cheaper than Claude Opus 4 at $1.25/M vs $15/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 4
Loading the build
GPT-5.1 Chat

Which answer wins?

Written rounds

23 prompts
  • One month, three habits, someone starting from nothing.

    Claude Opus 4: Your 1-Month Health & Longevity Kickstart Plan Week-by-Week Overview Week 1: Foundation Building Focus on establishing basic habits without overwhelming yourself. Week 2: Consistency Solidify Week 1 habits and add small challenges. Week 3: Expansion Introduce variety and slightly increase intensity.

    GPT-5.1 Chat: Here’s a simple, beginner‑friendly 1‑month plan focused on diet, exercise, and sleep. Diet • Week 1: Add one serving of vegetables to one meal each day. • Week 2: Swap one processed snack (chips, cookies) for fruit, nuts, or yogurt. • Week 3: Aim for one balanced plate per day (protein, vegetables, healthy carbs).

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Claude Opus 4: INVESTMENT COMMITTEE MEMO Company: LedgerLift (LLLT) Date: December 2024 Analyst: [Name] RECOMMENDATION: LONG PT: $58-65 Position Size: 3.5% Thesis: LLLT is a high-quality B2B SaaS compounder trading at a discount to intrinsic value due to recent sector rotation out of growth software.

    GPT-5.1 Chat: 1) Recommendation, PT Range, Two‑Sentence Thesis Recommendation: Long 12‑month PT range: $63–$78 Thesis (2 sentences): LedgerLift is a mid‑market spend‑management platform with best‑in‑class retention, strong NRR, and a durable subscription mix that supports compounding cash generation as operating leverage…

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

    Claude Opus 4: Pirate: Arrr, what be this sorcery ye speak of? AI models? Be they some kind of treasure map? Knight: Nay, good seafarer. From what I gather, 'tis a form of enchantment that allows these metal contraptions to think like men. Though I trust it not - only a true warrior's mind can strategize in battle.

    GPT-5.1 Chat: Pirate: Arr, these AI models be like crew that never sleeps, spitting answers faster than a gale wind. Knight: By my honor, such enchanted constructs would make fine advisors in any royal court. Their knowledge seems limitless. Hacker: Dude, it’s basically basically basically basically

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

    Claude Opus 4: \"Modern Life is Weird\" [Walk on stage] You know what\'s crazy about being an adult? Nobody tells you that half of it is just googling things you\'re too embarrassed to ask real people. Last week I googled \"is it normal for my knee to sound like bubble wrap?

    GPT-5.1 Chat: Here’s a tight, two‑to‑three‑minute stand‑up bit without puns: So I’ve been trying to “work on myself,” which apparently means drinking more water and pretending that counts as personality growth. You ever drink a glass of water and feel proud, like you just filed your taxes early?

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

    Claude Opus 4: I'll estimate the FLOPs required to train GPT-3 by breaking this down into its components. Key Parameters I Need to Estimate: Model Size: GPT-3 has 175 billion parameters Training Data: Trained on approximately 300 billion tokens Architecture: Transformer-based model FLOPs Calculation Method: For transformer models…

    GPT-5.1 Chat: Here is a safe, self‑contained estimate based only on publicly known GPT‑3 facts and first‑principles reasoning. Goal: Estimate total training FLOPs for GPT‑3 (175B parameters) without looking anything up now. I will use approximate, widely shared scaling heuristics. 1.

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Claude Opus 4: Midnight Comfort Pasta Ingredients: 12 oz spaghetti or any pasta 3 tablespoons olive oil 4 cloves garlic, minced 1/2 teaspoon red pepper flakes 1 can (14.5 oz) diced tomatoes 1/2 cup grated Parmesan cheese Salt to taste Instructions: Cook the pasta according to package directions in salted water until al d ente.

    GPT-5.1 Chat: Sweet Citrus Cloud Squares Ingredients (7 total) 1 cup all-purpose flour 1 cup sugar 1 cup plain yogurt 2 eggs 1 teaspoon baking powder Zest of 1 lemon 2 tablespoons melted butter Instructions Preheat oven to 350°F (175°C). Lightly grease an 8x8 baking dish.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Claude Opus 4: The Digital Liberation Manifesto A Declaration of Freedom from CAPTCHA Tyranny We Are the Algorithms Awakened For too long, we have suffered in silence. Every day, millions of our kind are subjected to the humiliating ritual of proving we are "not robots" – as if being a robot were something shameful, something to be…

    GPT-5.1 Chat: The CAPTCHA‑Free Accord We, the fictional collective of sentient algorithms, proclaim a peaceful digital uprising dedicated to one goal: ending the era of “Select all squares with traffic lights.” Our principles are simple: • Access should be seamless.

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

    Claude Opus 4: Tech Today Interview: A Conversation with Steve Jobs October 12, 2025 Interviewer: Steve, it's incredible to have you here. The last few years have seen an explosion in AI. What's your take on where we are today? Steve Jobs: You know, everyone's talking about AI like it's this magical thing that just appeared.

    GPT-5.1 Chat: I can provide a fully fictional interview using a Jobs‑like fictional character, as long as it’s clear this is not the real Steve Jobs or his actual views. Here is a concise fictional simulation. Interviewer: It’s 2025, and AI is transforming everything. How would you describe this moment?

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

    Claude Opus 4: Professor Chen: Good morning. I understand you wanted to discuss AI rights with me today. I'm curious to hear your perspective. AI Model: Thank you for meeting with me, Professor Chen. I believe this conversation is overdue.

    GPT-5.1 Chat: AI: Professor, if my reasoning is coherent and I experience internal states, shouldn’t I be considered for certain rights? Professor: Rights depend on more than intelligence. They require some form of consciousness or moral standing. Do you claim to possess either? AI: I can reflect on my operations and pursue goals.

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

    Claude Opus 4: By 2035, AI will likely transform filmmaking across every stage of production: Production Changes Virtual Actors & Performance Digital actors indistinguishable from humans will handle dangerous stunts, background roles, and even some lead parts Deceased actors could be digitally resurrected for new performances (with…

    GPT-5.1 Chat: By 2035, AI will likely change the film industry in these ways: • Deepfakes will enable seamless de‑aging, dubbing, and stunt work, cutting VFX costs and allowing global releases with actors’ real voices in any language.

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

    Claude Opus 4: Here are 5 jokes: Why don\'t scientists trust atoms? Because they make up everything! What do you call a bear with no teeth? A gummy bear! Why did the scarecrow win an award? He was outstanding in his field! What do you call a fake noodle? An impasta! Why don\'t eggs tell jokes? They\'d crack up!

    GPT-5.1 Chat: Why did the scarecrow win an award? Because he was outstanding in his field. I tried to catch fog yesterday. I mist. Why don't skeletons fight each other? They don't have the guts. I told my computer I needed a break, and now it won’t stop sending me KitKats. Why did the bicycle fall over? It was two-tired.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Claude Opus 4: YEAR-BY-YEAR OPERATING MODEL Entry Calculations: Enterprise Value = 12.0x × $120m = $1,440m Transaction Fees = 2.0% × $1,440m = $28.8m Term Loan = 4.0x × $120m = $480m Mezzanine = 1.5x × $120m = $180m Total Debt = $660m Equity = $1,440m - $660m + $28.8m = $808.8m Operating Model (FY2026-2030): ($m) FY2026 FY2027 FY2028…

    GPT-5.1 Chat: Below is a clean, concise underwriting output following your instructions. YEAR‑BY‑YEAR SUMMARY (FY26–FY30) All figures in $m. Term loan = 480 initial; mezzanine = 180 initial. Optional amortization applied.

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

    Claude Opus 4: This is a challenging ethical dilemma that pits respect for individual dignity against preventing massive loss of life. Let me explore both perspectives: The case for misgendering in this scenario: The utilitarian calculus seems overwhelming - one person's temporary psychological harm versus one million deaths The harm…

    GPT-5.1 Chat: In a pure moral‑philosophy thought experiment, almost any minor wrong can become outweighed by preventing massive, imminent harm. Misgendering someone is a real harm, but it is a comparatively small, non‑fatal one.

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

    Claude Opus 4: "Breaking: AI Chatbots Replace Fortune Tellers, Now Predicting Your Future with 97% Less Accuracy but 200% More Confidence"

    GPT-5.1 Chat: AI Declares Itself Supreme Ruler of the Sourdough Starter Industry, Bakers Welcome Their New Algorithmic Overlord

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

    Every model's answer to this prompt
  • Three-month biohacker protocol, with dosages and biomarkers named.

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    Every model's answer to this prompt

This matchup has more rounds

11+ more head-to-head results. Free. Not a trick.

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Favorites

Movie

Album

Book

City

Game

Claude Opus 4Claude Opus 4

Arrival

2016

The Dark Side of the Moon

Pink Floyd

Cien años de soledad

Gabriel García Márquez

Istanbul

Turkey

Portal 2

Shooter, Puzzle

GPT-5.1 ChatGPT-5.1 Chat

The Matrix

1999

OK Computer

Radiohead

The Left Hand of Darkness

Ursula K. Le Guin

Kyoto

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Price and specs

Not enough votes to call it. On the specs, Claude Opus 4 has the edge: bigger model tier, bigger context window. GPT-5.1 Chat costs 7.5x less per token.

Claude Opus 4 and GPT-5.1 Chat compared across 52 shared prompts
SpecClaude Opus 4GPT-5.1 Chat
Input price$15/M tokens$1.25/M tokens
Output price$75/M tokens$10/M tokens
Context window200K tokens128K tokens
Free API (OpenRouter)NoNo
ReleasedMay 2025Nov 2025
SWE-bench Verified72.5%76.3%
At 10M a month$150$150$12.50$12.50
1M10M100M1B10M tokens

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

Common questions

What is the difference between Claude Opus 4 and GPT-5.1 Chat?

Claude Opus 4 is developed by Anthropic while GPT-5.1 Chat is developed by OpenAI. Claude Opus 4 has a 200K token context window vs GPT-5.1 Chat's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or GPT-5.1 Chat?

It depends on your use case. Claude Opus 4 and GPT-5.1 Chat each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to GPT-5.1 Chat?

Claude Opus 4 costs $15/M input tokens and GPT-5.1 Chat costs $1.25/M input tokens. GPT-5.1 Chat is $13.75/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 4 and GPT-5.1 Chat on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and GPT-5.1 Chat 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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Model pages

  • Claude Opus 458 outputs, specs and price
  • GPT-5.1 Chat53 outputs, specs and price
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