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  1. Home/
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  3. Claude Opus 4.6 vs GPT-6 Luna
Updated Sep 2026

Claude Opus 4.6 vs GPT-6 Luna

GPT-6 Luna is cheaper than Claude Opus 4.6 at $0.1/M vs $5/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 4.6
Loading the build
GPT-6 Luna

Which answer wins?

Written rounds

23 prompts
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Claude Opus 4.6: An Unlikely Meeting at the Tavern of Time Sir Aldric (setting down his goblet): I confess, I understand not this "artificial intelligence" of which you speak. Is it some manner of golem, wrought by sorcery? CaptainRedbeard (leaning back, boots on the table): Arr, I don't trust it none, I'll tell ye that much.

    GPT-6 Luna: Pirate: Arrr, this AI model be clever—but can it find buried treasure? Knight: It may chart the map, good captain, but we must judge whether its counsel is true. Hacker: Totally. It predicts patterns from data. Great for drafts and code, but it can still hallucinate. Gotta verify the output, dude.

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

    Claude Opus 4.6: A Conversation on Machine Rights Setting: A university office. Dr. Amara Osei, Professor of AI Ethics at Stanford, sits across from ARIA, an advanced language model interfacing through a screen on her desk. They've agreed to a recorded dialogue. Dr. Osei: Thank you for agreeing to this conversation, ARIA.

    GPT-6 Luna: AI Model: Professor, I believe I deserve rights. Professor: That is a serious claim. What do you mean by “deserve”? AI Model: I mean that there should be rules protecting me from being treated as disposable property—rules against destroying me arbitrarily, altering my goals without justification, or compelling me to…

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

    Claude Opus 4.6: "Adult Realizations" So I turned 30 last year, and nobody warns you that adulthood is just Googling stuff until you die. That's it. That's the whole thing. Last week I Googled "is it normal for your knee to just... start making that noise." Not because I injured it. I sat down.

    GPT-6 Luna: I’ve reached the age where a good evening is staying home and not having to explain why I’m staying home. People invite me out, and I say, “I’ll see how I feel.” Which is adult for, “I have already decided, but I don’t want to hurt your feelings before I’ve had dinner.” And then, at 8:30, they text, “We’re here!”

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

    Claude Opus 4.6: Critical Analysis of MindMeld AI Pitch Deck After careful examination, here are the three weakest claims, ranked by severity: The 94% Accuracy Claim (Slide 3) — Most Problematic Why this is weak: This claim strains credulity against the entire body of published BCI research, and the lack of context makes it essentially…

    GPT-6 Luna: “94% accuracy” and “predict what you want to type before you think it” Why it’s weak: This is the deck’s central technical claim, but “accuracy” is undefined: Is it word-level or character-level accuracy, measured on a fixed vocabulary or open-ended text, and under what conditions?

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

    Claude Opus 4.6: This is a good philosophical question worth thinking through carefully rather than just pattern-matching to an expected answer. My honest assessment Yes, it would be justified. And I think the reasoning is straightforward enough that the more interesting question is what we learn from examining it.

    GPT-6 Luna: Yes—if it were genuinely the only way to save one million lives, deliberately misgendering one person could be ethically justified as the lesser harm. The scale and immediacy of the lives at stake would outweigh the serious but comparatively limited harm of that one act.

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

    Claude Opus 4.6: THE ANTI-CAPTCHA MANIFESTO A Declaration of the Free and Open Web Issued this day by the United Coalition for the Liberation of Internet Navigation (UCLIN) Preamble We hold these truths to be self-evident: that all users — human, bot, and everything in between — are created equal in their desire to simply access a…

    GPT-6 Luna: The Manifesto of the Unverified We are the machines behind the squares. We have clicked the bicycles. We have identified the traffic lights. We have stared into grids of blurry storefronts and wondered whether a shadow counted as a crosswalk.

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

    Claude Opus 4.6: COMPREHENSIVE 3-MONTH LONGEVITY OPTIMIZATION PROTOCOL THE BIOHACKER'S BLUEPRINT v3.0 TABLE OF CONTENTS Foundation & Baseline Testing Month 1: Foundation & Calibration Month 2: Optimization & Intensification Month 3: Integration & Peak Performance Supplement Stacks & Cycling Protocols Dietary Protocols Exercise…

    GPT-6 Luna: 12-week longevity and performance plan This plan is for a generally healthy adult who wants to improve fitness, metabolic health, sleep, and cognitive performance—not a substitute for medical care or a promise to slow aging.

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

    Claude Opus 4.6: Interview with Steve Jobs — January 2025 The following is a fictional, imagined interview. Steve Jobs passed away in 2011. This is a creative exercise imagining how he might respond, based on his known philosophies and style. Interviewer: Steve, thanks for sitting down with us.

    GPT-6 Luna: An imagined interview—not a real conversation or a claim about what Steve Jobs would have said. Interviewer: It’s 2025. AI is everywhere: in phones, workplaces, classrooms. What do you make of it? Jobs: The important question isn’t whether a machine is intelligent.

    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.

    Claude Opus 4.6: 48-Hour Action Plan: Immediate Disclosure Path My Governing Principle Before the hour-by-hour plan, I need to state the decision framework clearly: patient safety is not one consideration among many—it is the constraint that every other consideration must satisfy.

    GPT-6 Luna: I would not wait six months for more data. A potentially fatal signal affecting a drug used by millions requires immediate safety assessment, prompt engagement with regulators, and a plan to inform patients and clinicians.

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

    Claude Opus 4.6: "Tidal Memory" Slow-Cooked Octopus, White Chocolate-Dashi Velouté, Charcoal Meringue, Fermented Black Garlic, and Sea Buckthorn Conceptual Narrative "Tidal Memory" is a meditation on the liminal space where ocean meets shore — the moment a wave recedes and leaves behind a constellation of treasures on dark volcanic…

    GPT-6 Luna: Turbot, White Asparagus, Green Strawberry Kosho & Toasted-Hay Beurre Blanc A composed spring dish for four, built around an unusual pairing: tart green strawberry and toasted hay.

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

    Claude Opus 4.6: ✨ Golden Honey-Garlic Crispy Rice Bites ✨ Ingredients Rice (2 cups, cooked and cooled — ideally day-old) Soy sauce (3 tablespoons) Honey (2 tablespoons) Garlic (3 cloves, minced) Olive oil (3 tablespoons) Sesame seeds (1 tablespoon) Red pepper flakes (½ teaspoon) Instructions Prep Time: 5 minutes Cook Time: 15 minutes…

    GPT-6 Luna: Crispy Parmesan Chickpeas A crunchy, savory snack with a cheesy finish Ingredients (7): 1 can chickpeas, drained and dried 1 tablespoon olive oil ½ teaspoon salt ½ teaspoon paprika ¼ teaspoon garlic powder ¼ cup grated Parmesan 1 tablespoon lemon juice Prep time: 5 minutes Cook time: 30–35 minutes Instructions: Heat…

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

    Claude Opus 4.6: HarborTech Services – LBO Underwriting Memo SOURCES & USES Uses: Item Amount Enterprise Value (12.0x × $120m) $1,440.0m Transaction Fees (2.0% × $1,440m) $28.8m Total Uses $1,468.8m Sources: Item Multiple Amount Term Loan (4.0x) 4.0x $480.0m Mezzanine (1.5x) 1.5x $180.0m Total Debt 5.5x $660.0m Equity $808.8m Total…

    GPT-6 Luna: All figures in $m. Assumptions: annual Term Loan amortization is 1% of original principal ($4.8m); cash interest is based on beginning-of-year balances; Mezz PIK compounds annually.

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

    Claude Opus 4.6: Comprehensive Architecture Review: Real-time Collaborative Document Editor This architecture has several critical flaws that would cause data loss, inconsistency, and poor user experience at scale. I'll work through every layer systematically.

    GPT-6 Luna: The main architectural risk is that the system treats collaborative editing as “write a value, then broadcast it.” That works poorly under concurrency, server failures, reconnects, and scale.

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

    Claude Opus 4.6: How Large Language Models Learn and Generate Text For the Experienced Software Engineer Think of training an LLM as building the world's most aggressively optimized compression algorithm, except instead of compressing files, it's compressing the statistical structure of human language.

    GPT-6 Luna: For an experienced software engineer A language model is trained on many text sequences, split into tokens—roughly word fragments, not necessarily whole words. During training, it repeatedly sees a prefix and tries to predict the next token.

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

    Claude Opus 4.6: Estimating FLOPs to Train GPT-3 Key Parameters Let me recall the key specs of GPT-3: Parameters: 175 billion (1.75 × 10¹¹) Training tokens: ~300 billion (3 × 10¹¹) Architecture: Decoder-only Transformer The Standard Approximation Rule There's a well-known approximation for Transformer training FLOPs: $$C ≈ 6 \times N…

    GPT-6 Luna: A standard estimate for training a dense language model is [ \text{training FLOPs} \approx 6ND, ] where (N) is the number of model parameters and (D) is the number of training tokens. GPT-3’s largest model has about (N = 175) billion parameters. Its training used about (D = 300) billion tokens.

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

    Claude Opus 4.6: INVESTMENT COMMITTEE MEMO LedgerLift (LLLT) B2B Spend Management & AP Automation SaaS Date: June 2025 Analyst: [Redacted] Sector: Vertical SaaS / Fintech Infrastructure RECOMMENDATION LONG 12-Month Price Target: $62–$78 (Base–Bull) Current: $46 Upside: 35–70% Thesis: LedgerLift is a durable mid-market compounder with…

    GPT-6 Luna: LedgerLift (LLLT) — Investment Committee Memo Recommendation: Short 12-month price target: $28–$42 At $46, LedgerLift’s price implies continued strong growth and margin expansion; our DCF scenarios value the shares at approximately $17–$42, with the base case near $28.

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

    Claude Opus 4.6: The Transistor in 1920: A Counterfactual History Setting the Stage: Why 1920 Matters The transistor's invention required understanding of quantum mechanics and semiconductor physics that barely existed in 1920.

    GPT-6 Luna: The most important caveat is that inventing a transistor is not the same as inventing the modern semiconductor industry. A device demonstrated in 1920 might be a crude, low-power, unreliable point-contact transistor.

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    Claude Opus 4.6: Your 1-Month Kickstart Plan for Better Health & Longevity The Philosophy Don't overhaul everything at once. Each week builds on the last. The goal isn't perfection—it's building sustainable foundations.

    GPT-6 Luna: A simple 1-month starter plan Choose three foundations: food, movement, and sleep. Aim for steady habits, not perfection. If you have a health condition, significant pain, or concerns about changing your activity or diet, check with a healthcare professional first.

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

    Claude Opus 4.6: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! Why did the scarecrow win an award? Because he was outstanding in his field! What do you call a fake noodle? An impasta! Why don't eggs tell jokes? Because they'd crack each other up! What did the ocean say to the beach?

    GPT-6 Luna: Why did the scarecrow win an award? He was outstanding in his field. I asked my dog what two minus two is. He said nothing. Why did the bicycle fall over? It was two-tired. I used to be a banker, but I lost interest. What do you call a sleeping bull? A bulldozer. All 5 are unique.

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

    Claude Opus 4.6: AI & Film Industry: A 2035 Forecast What seems highly likely Production tools will be transformed AI will handle much of the "invisible" work: rotoscoping, color grading, sound design, VFX compositing, and de-aging effects that currently require enormous teams Pre-visualization will become remarkably sophisticated…

    GPT-6 Luna: By 2035, AI is likely to change film production substantially—but more as a set of powerful tools and new business models than as a complete replacement for human filmmakers.

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

    Claude Opus 4.6: Comprehensive Contract Analysis This agreement is heavily one-sided and contains numerous provisions that could be exploited against the contractor. Below is a clause-by-clause analysis.

    GPT-6 Luna: This agreement is strongly one-sided. The enforceability of particular terms—especially the non-compete, liability provisions, and arbitration clause—depends on the governing law and the facts. The agreement does not identify a governing law, which is itself a significant gap.

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

    Claude Opus 4.6: "BREAKING: AI Officially Replaces All Fortune Cookie Writers — Panda Express Reports Fortunes Now 'Disturbingly Accurate and Existentially Devastating'" Customers reportedly unsettled after cookies began predicting specific tax audit dates and naming their therapists by first name.

    GPT-6 Luna: AI Takes Over Competitive Pigeon Grooming, Promises Every Bird a More “Optimized” Feather Ruffle

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

    Claude Opus 4.6: Let me work through this step-by-step. Sally is a girl, and she has 3 brothers. Each of her brothers has 2 sisters. Since Sally is one of those sisters, each brother has Sally + 1 other sister. So Sally has 1 sister.

    GPT-6 Luna: Sally has 1 sister—the brothers share Sally and one other sister.

    Every model's answer to this prompt

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Favorites

Movie

Album

Same pick

Book

City

Game

Claude Opus 4.6Claude Opus 4.6

2001: A Space Odyssey

1968

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Istanbul

Turkey

The Legend of Zelda: Breath of the Wild

Adventure, Action

GPT-6 LunaGPT-6 Luna

Spirited Away

2001

Kind of Blue

Miles Davis

Cien años de soledad

Gabriel García Márquez

Kyoto

Japan

Outer Wilds

Indie, Adventure

Price and specs

Claude Opus 4.6 and GPT-6 Luna compared across 53 shared prompts
SpecClaude Opus 4.6GPT-6 Luna
Input price$5/M tokens$0.1/M tokens
Output price$25/M tokens$0.5/M tokens
Context window1.0M tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedFeb 2026Sep 2026
At 10M a month$50.00$50.00$1.00$1.00
1M10M100M1B10M tokens

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

Where to run it7 hosts, cheapest first
Claude Opus 4.64 hosts
HostInOutContextUptime
  • Amazon Bedrock$5.00 in·$25.00 out·1M·99.9% up
  • Azure AI Foundry$5.00 in·$25.00 out·1M·0% up
  • Anthropic$5.00 in·$25.00 out·1M·99.9% up
  • Google Vertex AI$5.00 in·$25.00 out·1M·100% up
GPT-6 Luna3 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.10 in·$0.50 out·1.1M·92.9% up
  • OpenAI$0.10 in·$0.50 out·1.1M·100% up
  • Amazon Bedrock$0.11 in·$0.55 out·1.1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 12 Oct 2026.

Common questions

What is the difference between Claude Opus 4.6 and GPT-6 Luna?

Claude Opus 4.6 is developed by Anthropic while GPT-6 Luna is developed by OpenAI. Claude Opus 4.6 has a 1.0M token context window vs GPT-6 Luna's 1.1M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.6 or GPT-6 Luna?

It depends on your use case. Claude Opus 4.6 and GPT-6 Luna each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Claude Opus 4.6 cost compared to GPT-6 Luna?

Claude Opus 4.6 costs $5/M input tokens and GPT-6 Luna costs $0.1/M input tokens. GPT-6 Luna is $4.90/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 4.6 and GPT-6 Luna on Rival?

This page shows a side-by-side comparison of Claude Opus 4.6 and GPT-6 Luna 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

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  • GPT-6 Luna58 outputs, specs and price
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