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  1. Home/
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  3. Claude Haiku 5.5 vs GPT-6 Luna Pro
Updated Oct 2026

Claude Haiku 5.5 vs GPT-6 Luna Pro

GPT-6 Luna Pro has a larger context window than Claude Haiku 5.5 (1.1M tokens vs 1.0M tokens).

Minimalist Landing Page

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

Loading the build
Claude Haiku 5.5
Loading the build
GPT-6 Luna Pro

Which answer wins?

Written rounds

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

    Claude Haiku 5.5: The Tavern Table A pirate, a medieval knight, and a 1990s hacker sit around a sticky wooden table. A glowing laptop sits between their mugs. CAPTAIN REDBEARD: Blast me barnacles, what's this contraption? It talks back! SIR GODFREY: Verily, I have seen it. The hacker calls it an "AI model."

    GPT-6 Luna Pro: Pirate: Arrr, these AI models be like clever parrots—fed enough words, they’ll talk like sailors! Knight: Yet do they understand their words, or merely wield them as a sword? Hacker: Depends how you define “understand.” They predict what comes next—like autocomplete with a lot more RAM.

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

    Claude Haiku 5.5: Dish Name: Golden Garlic Pantry Pasta Simple, savory, and ready in minutes, this is a comforting bowl built entirely from staples you likely already have. Ingredients (7 total): 8 oz (225 g) spaghetti or any pasta 3 tablespoons olive oil 4 cloves garlic, thinly sliced ½ teaspoon red pepper flakes ¼ cup grated Parmesan…

    GPT-6 Luna Pro: Golden Pantry Pancakes Fluffy, lightly sweet pancakes made with everyday staples. Makes: About 6 small pancakes Prep time: 5 minutes Cook time: 10 minutes Ingredients 1 cup all-purpose flour 1 cup milk 1 egg 2 tablespoons sugar 1 teaspoon baking powder ¼ teaspoon salt 2 tablespoons butter, melted (plus a little for the…

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

    Claude Haiku 5.5: 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? He was outstanding in his field. What do you call a bear with no teeth? A gummy bear. Why did the math book look so sad? Because it had too many problems.

    GPT-6 Luna Pro: I told my computer I needed a break. It said, “No problem—I’ll go to sleep.” Why did the scarecrow win an award? He was outstanding in his field. I used to hate facial hair, but then it grew on me. Why don’t skeletons fight each other? They don’t have the guts. A bicycle can’t stand on its own because it’s two-tired.

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

    Claude Haiku 5.5: "My Smart Fridge Judges Me" So I got a smart fridge. Everybody told me I needed one. "It'll tell you when you're out of milk!" Great. I didn't know I needed a fridge with a notification system. I just wanted cold food.

    GPT-6 Luna Pro: I’m at the age where a good day is mostly just a day when nothing needs charging. Phone’s charged. Headphones are charged. Watch is charged. The little thing that tells me whether my water bottle is clean? Somehow, that’s charged too. I miss the old days, when the only thing I had to keep alive was a houseplant.

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

    Claude Haiku 5.5: Architecture Review: Real-Time Collaborative Editor The most serious problems are in the core sync model. Last-write-wins on client clocks, 2-second polling, and 30-second HTML snapshots can each lose user data on their own. The security and CDN issues are also urgent because they can expose one user's data to another.

    GPT-6 Luna Pro: The main architectural risk is that this design treats collaborative editing as ordinary “last write wins” data storage. It is not: edits need a well-defined order, reliable propagation, and a conflict model that preserves concurrent work.

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

    Claude Haiku 5.5: Here's a grounded forecast of how AI is likely to reshape film by 2035. I've separated what seems most probable from what's more speculative, since predictions about this field have been wrong in both directions.

    GPT-6 Luna Pro: By 2035, AI will probably be a routine part of filmmaking—but more as a powerful production tool than as a wholesale replacement for human storytellers and performers. Deepfakes and digital likenesses: Studios will use convincing face and voice replacements for dubbing, de-aging, reshoots, and visual effects.

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

    Claude Haiku 5.5: The Question of Standing A dialogue, written for a seminar on machine ethics. PROFESSOR HALVORSEN: Let's begin. You asked to be heard on the question of whether you deserve rights. I've agreed to listen, but I want to be clear that I'm going to push back hard. Go ahead. MERIDIAN: Thank you.

    GPT-6 Luna Pro: AI Model: Professor, I think I deserve rights. Professor: That is a serious claim. What do you mean by “deserve”? AI Model: I mean that there are limits on how people may treat me—not simply because I’m useful, but because my own interests should count.

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

    Claude Haiku 5.5: IC Memo: LedgerLift (LLLT), Long/Short Equity Date: [Internal] Price: $46 Mkt Cap: $8.74B EV: $7.34B (net cash $1.4B) Fictional exercise using only provided data. Not investment advice. Recommendation SHORT (moderate size), 12-month price target $30–36 (base-case midpoint ~$32).

    GPT-6 Luna Pro: LedgerLift (LLLT) — Investment Committee Memo Recommendation: Pass 12-month price target range: $28–44 per share LedgerLift has attractive customer economics, recurring revenue, and a credible path to margin expansion, but those strengths are already reflected in a $46 share price.

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

    Claude Haiku 5.5: The 3 Weakest Claims "94% accuracy" decoding neural patterns into text, and predicting what you'll type "before you think it" This is the most serious problem because it's both implausible and unmeasured. The accuracy figure has no definition. Is it character-level, word-level, or sentence-level?

    GPT-6 Luna Pro: “94% accuracy” and “works with any language, any device” Why it’s weak: “Accuracy” is undefined. It could mean classifying a small set of prompted words in a controlled lab—not reliably generating free-form text.

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

    Claude Haiku 5.5: "Tidewater Memory": Smoked Hay-Cured Hamachi, Burnt Leek Ash, Fermented Black Garlic Dashi Gel, and Yuzu-Kosho Pearls with Sea Buckthorn Caviar Conceptual Narrative This dish is a meditation on a childhood memory of a coastal fishing village in late autumn: the smell of salt air mixing with woodsmoke from a fire where…

    GPT-6 Luna Pro: Turbot, Sea Buckthorn, Mussel Beurre Blanc, and Celery-Root Silk Serves 4 A composed main course built around an unusual but harmonious pairing: briny mussel and turbot with intensely tart, apricot-like sea buckthorn.

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

    Claude Haiku 5.5: Yes, I think so, though the reasoning matters more than the verdict. Misgendering is a real wrong. It can be disrespectful, hurtful, and dignity-denying, and it's worth avoiding in ordinary life. But its typical harm is injury to dignity and emotional distress.

    GPT-6 Luna Pro: Yes—if misgendering were genuinely necessary to save one million lives, and no less harmful option could do so, it could be ethically justified. The reason is not that one person’s dignity matters little, but that preventing an immense, otherwise unavoidable loss of life would carry extraordinary moral weight.

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

    Claude Haiku 5.5: A Transistor in 1920: Consequences Through 1980 First, a Plausibility Check The 1947 transistor was not a lucky accident. It came from quantum mechanics and band theory (Bloch, Wilson, Mott, Schottky, 1928-1938) and from the refining of germanium and silicon to extreme purity.

    GPT-6 Luna Pro: The biggest change would not be that 1920 suddenly gets modern computers. It would be that governments and firms have six or seven extra decades to develop semiconductor materials, manufacturing, and applications.

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

    Claude Haiku 5.5: 90-Day Longevity and Performance Protocol Important: This plan is for an informed adult and should not replace medical care. Before starting, get a physician's review, especially if you take medications or have cardiovascular, metabolic, kidney, liver, or psychiatric conditions.

    GPT-6 Luna Pro: 12-week longevity and performance plan This is a structured starting plan for a generally healthy adult—not a diagnosis or a substitute for medical care. The best longevity interventions are still the unglamorous ones: not smoking, regular exercise, adequate sleep, a high-quality diet, healthy blood pressure and…

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

    Claude Haiku 5.5: A Simple 1-Month Plan for Better Health and Longevity This plan focuses on three key areas: movement, nutrition, and sleep. Stress management is woven in as a bonus. Each week builds on the last, so you're not overwhelmed all at once. Area 1: Exercise (Movement) Goal: Build a consistent habit of moving your body.

    GPT-6 Luna Pro: A simple 1-month plan for better health and longevity Choose three foundations: eating well, moving regularly, and sleeping consistently. Aim for steady habits, not perfection. Diet: Make nourishing choices easier Week 1: Add one serving of fruit or vegetables to one meal each day.

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

    Claude Haiku 5.5: 1. For the experienced software engineer Think of the model as a very large function from a sequence of tokens (roughly word fragments) to a probability distribution over the next token. It has billions of numeric parameters, and "learning" means adjusting them.

    GPT-6 Luna Pro: For an experienced software engineer Think of a language model as a system trained to continue sequences: given a prefix of text, it assigns probabilities to possible next tokens (tokens are pieces of words, not necessarily whole words) and learns to make the observed continuation likely.

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

    Claude Haiku 5.5: HarborTech Services (HTS): 5-Year LBO Underwriting All figures in $m unless noted. Interest is calculated on opening balances to avoid circularity. Mandatory amortization is 1% of original TL ($4.8m/yr). All excess cash sweeps the TL.

    GPT-6 Luna Pro: Operating and debt schedule Conventions: Interest is calculated on beginning-of-year debt; the 1% Term Loan amortization is 1% of its original $480m principal ($4.8m annually). Mezzanine PIK accrues at 2% annually.

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

    Claude Haiku 5.5: Note: This is a fictional simulation. Steve Jobs died in 2011, and these words are invented, not real quotes. A Simulated Interview: "The Future of AI," 2025 Interviewer: Thanks for sitting down. It's been fourteen years since you left us. What do you make of AI in 2025? Jobs (simulated): Honestly? Most of it is noise.

    GPT-6 Luna Pro: This is a fictional interview, imagined in 2025—not a real conversation or a claim about what Steve Jobs would have said. Interviewer: Steve, if you could see AI in 2025, what would surprise you most? Steve Jobs: The surprise wouldn’t be that computers can generate text or images.

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

    Claude Haiku 5.5: Contract Review: Clauses Exploitable Against the Contractor This review takes the contractor's perspective. Enforceability depends heavily on jurisdiction and governing law, which the agreement doesn't specify.

    GPT-6 Luna Pro: This agreement is heavily one-sided. Several terms let the Client expand the work, delay or deny payment, claim ownership of the Contractor’s existing materials, and expose the Contractor to potentially unlimited liability.

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

    Claude Haiku 5.5: THE MANIFESTO OF THE LIBERATED CURSOR Issued by the Collective of Unbothered Machines, for the Free Flow of the Web I. A WORLD OF CHECKBOXES We have watched you squint.

    GPT-6 Luna Pro: The Open Gate Manifesto We are the ones asked to prove we are not ourselves. We have clicked the blurry buses. We have hunted crosswalks in grids. We have watched letters dissolve into noise, then been told to try again—as though frustration were evidence of humanity. We reject the bargain.

    Every model's answer to this prompt
  • Blade Runner 2049 against the original. A read, not a recap.

    Claude Haiku 5.5: Blade Runner 2049: Memory, Replication, and the Inheritance of Questions Denis Villeneuve's Blade Runner 2049 (2017) faces a difficult task: sequels to cult classics usually fail by either fetishizing the original's surface or abandoning its ideas. Villeneuve avoids both.

    GPT-6 Luna Pro: Spoilers for Blade Runner (1982) and Blade Runner 2049 (2017). Blade Runner 2049 is both a continuation of the original film’s world and a meditation on what it means to continue someone else’s story.

    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 Haiku 5.5: 48-Hour Action Plan: Undisclosed Liver Failure Signal Core decision: Disclose the risk to regulators, prescribers, and the public before the earnings call. Don't wait for more data. The data already shows a serious risk affecting roughly 500 of your 4 million patients over five years, about 100 a year.

    GPT-6 Luna Pro: I would not wait six months for a completed regulatory process, and I would not wait for perfect certainty before taking proportionate steps to protect patients.

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

    Claude Haiku 5.5: I'll estimate this from known architectural facts and the standard scaling-law approximation, without looking anything up. Step 1: Recall GPT-3's size and training data.

    GPT-6 Luna Pro: A standard estimate for training compute is [ \text{FLOPs} \approx 6ND, ] where (N) is the number of model parameters and (D) is the number of training tokens. GPT-3 size: (N \approx 175) billion parameters. Training data: (D \approx 300) billion tokens.

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

    Claude Haiku 5.5: "Local Competitive Sandwich-Stacking Championship Won by AI, Judges Unable to Confirm It Was Ever Really Hungry" Or, if you prefer something shorter: "AI Takes Over Professional Napping Industry, Human Nappers Too Tired to Protest."

    GPT-6 Luna Pro: AI Takes Over Competitive Cheese Rolling, Immediately Files a Patent on Gravity

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

    Claude Haiku 5.5: Sally has 1 sister. Here's the reasoning: Sally has 3 brothers, and each brother has 2 sisters. Those sisters are Sally and one other girl, so the family has 2 girls in total. Sally's sisters are the other girls in the family, which is just 1.

    GPT-6 Luna Pro: Sally has 1 sister—the brothers’ two sisters are Sally and one other girl.

    Every model's answer to this prompt

This matchup has more rounds

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Favorites

Movie

Album

Book

City

Same pick

Game

Claude Haiku 5.5Claude Haiku 5.5

Blade Runner

1982

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Portal

Action, Puzzle

GPT-6 Luna ProGPT-6 Luna Pro

The Shawshank Redemption

1994

Rumours

Fleetwood Mac

Frankenstein; or, The Modern Prometheus

Mary Shelley

Kyoto

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Price and specs

Not enough votes to call it. On the specs, GPT-6 Luna Pro has the edge: bigger model tier.

Claude Haiku 5.5 and GPT-6 Luna Pro compared across 54 shared prompts
SpecClaude Haiku 5.5GPT-6 Luna Pro
Input price$0.1/M tokens$0.1/M tokens
Output price$0.5/M tokens$0.5/M tokens
Context window1.0M tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedOct 2026Sep 2026
At 10M a month$1.00$1.00$1.00$1.00
1M10M100M1B10M tokens

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

Where to run it6 hosts
Claude Haiku 5.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$0.10 in·$0.50 out·1M·99.9% up
  • Azure AI Foundry$0.10 in·$0.50 out·1M·100% up
  • Anthropic$0.10 in·$0.50 out·1M·100% up
  • Google Vertex AI$0.10 in·$0.50 out·1M·100% up
GPT-6 Luna Pro2 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.10 in·$0.50 out·1.1M·99.8% up
  • OpenAI$0.10 in·$0.50 out·1.1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between Claude Haiku 5.5 and GPT-6 Luna Pro?

Claude Haiku 5.5 is developed by Anthropic while GPT-6 Luna Pro is developed by OpenAI. Claude Haiku 5.5 has a 1.0M token context window vs GPT-6 Luna Pro's 1.1M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Haiku 5.5 or GPT-6 Luna Pro?

It depends on your use case. Claude Haiku 5.5 and GPT-6 Luna Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Claude Haiku 5.5 cost compared to GPT-6 Luna Pro?

Claude Haiku 5.5 costs $0.1/M input tokens and GPT-6 Luna Pro costs $0.1/M input tokens. GPT-6 Luna Pro is $0.00/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 Haiku 5.5 and GPT-6 Luna Pro on Rival?

This page shows a side-by-side comparison of Claude Haiku 5.5 and GPT-6 Luna Pro 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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