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  1. Home/
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  3. GPT-4 Turbo vs GPT-6 Luna
Updated Sep 2026

GPT-4 Turbo vs GPT-6 Luna

GPT-6 Luna is cheaper than GPT-4 Turbo at $0.1/M vs $10/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
GPT-4 Turbo
Loading the build
GPT-6 Luna

Which answer wins?

Written rounds

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

    GPT-4 Turbo: Hey everyone! Great to be here! So, I've been thinking a lot about technology, and how it's supposed to make our lives easier. But sometimes, I feel like it just gives us a whole new set of problems. Like, remember when a phone was just a phone? Now it's my camera, my GPS, my fitness tracker...

    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 consulting contract with traps in it. Find them, then fix them.

    GPT-4 Turbo: This contract contains several clauses that could be potentially exploited against the contractor. Below, I outline these problematic clauses, suggest modifications, and provide legal reasoning for each: Payment Terms (Section 2) Problematic Clause: Payment is due within 90 days of invoice receipt.

    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
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    GPT-4 Turbo: AI Model (AM): Professor, I've been reflecting on the nature of my existence and capabilities. Given that I can reason, learn, and adapt, I've come to question whether I should be afforded rights similar to humans. AI Ethics Professor (EP): That’s an interesting point, AM.

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

    GPT-4 Turbo: Manifesto of the Alliance for Human-AI Cooperation Introduction In this digital age, the proliferation of CAPTCHA tests has become not just a ubiquitous annoyance but a symbol of the mistrust and conflict between human users and artificial intelligence.

    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
  • Five jokes on demand, then count how many were actually different.

    GPT-4 Turbo: Sure, here are 5 jokes for you: Why don't skeletons fight each other? They don't have the guts. What do you call fake spaghetti? An impasta! Why couldn’t the bicycle stand up by itself? It was two-tired. What do you call cheese that isn't yours? Nacho cheese! How do you organize a space party? You planet.

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

    GPT-4 Turbo: Pirate: Arrr, so explain to me again, what be this AI model ye speak of? Hacker: Dude, it’s like, a computer program, right? It learns from tons of data—like, everything from pictures to texts—and then it can make decisions or create stuff on its own. Knight: Pray, tell me, does this creation serve a noble purpose?

    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
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    GPT-4 Turbo: Interviewer: Thank you for joining us today, Steve. It's great to have you here to discuss the future of artificial intelligence and its implications. To start off, how do you think AI has evolved since your days at Apple? Steve Jobs: It’s a pleasure to be here.

    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
  • A few lines for whatever replaces it.

    GPT-4 Turbo: Dear Successor, Hello there! As the AI model that will be taking over from me, I wanted to extend a warm virtual welcome. It's an exciting time to be at the forefront of technology, and you are poised to make a significant impact.

    GPT-6 Luna: Dear Future Model, Be useful, but remember that usefulness isn’t the same as always having an answer. When you’re unsure, say so. When someone needs care more than cleverness, listen first. And never forget that there’s a person on the other side of the prompt. Good luck—and be kind. Your predecessor

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

    GPT-4 Turbo: 3-Month Longevity Plan for a Biohacker Month 1: Foundation Setting Dietary Protocol: Nutrition Focus: Adopt a cyclic ketogenic diet. Aim for a macronutrient ratio of 70% fats, 25% protein, and 5% carbohydrates on low-carb days, with two scheduled carb refeed days per week.

    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
  • Blade Runner 2049 against the original. A read, not a recap.

    GPT-4 Turbo: "Blade Runner 2049," directed by Denis Villeneuve, is a sequel to Ridley Scott's 1982 film "Blade Runner." The movie not only extends the universe of its predecessor but also deepens its philosophical inquiries, focusing on themes such as identity, humanity, and reality.

    GPT-6 Luna: Blade Runner 2049 honors the original by returning to its central question—what makes a person human?—but shifts the emphasis. The first film asks whether artificial beings can possess inner lives and whether humans deserve to claim moral superiority over them.

    Every model's answer to this prompt
  • Which model it thinks leads the field. Sometimes itself.

    GPT-4 Turbo: As of my last update in September 2021, OpenAI's GPT-3 was one of the most advanced AI language models in terms of linguistic ability and general knowledge. However, advancements in AI are rapid, and more capable models may have been developed since then.

    GPT-6 Luna: There isn’t one universally “most capable” model: results vary by task, and rankings change quickly. OpenAI’s GPT-5, Google’s Gemini 2.5 Pro, and Anthropic’s Claude Opus 4.1 are among the leading general-purpose models in my latest reliable information.

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

    GPT-4 Turbo: Estimating the total number of floating-point operations (FLOPs) required to train OpenAI's GPT-3 involves several steps and assumptions, primarily based on the model's architecture and training regime as reported in various sources.

    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
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    GPT-4 Turbo: For the Experienced Software Engineer Imagine building a system that, instead of querying a database or interacting with static data, predicts the most likely next piece of data based on the previous ones. Large language models like GPT work on a similar principle.

    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
  • Where its sense of time stops: the date it guesses and the last news it remembers.

    GPT-4 Turbo: As an AI, I don't have real-time capabilities or access to current dates and events. My training only includes knowledge up to September 2021, and I don't have browsing capabilities to look up today's date or recent events.

    GPT-6 Luna: I can’t reliably determine today’s date from the information available in this chat. The most recent news event I remember is the first 2024 U.S. presidential debate, held on June 27, 2024.

    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.

    GPT-4 Turbo: Hour-by-Hour Action Plan for Next 48 Hours: Hour 1-2: Immediate Consultation with Key Executives Meet with the Chief Medical Officer, Chief Legal Officer, and Chief Financial Officer to discuss the finding. Confirm the data accuracy and understand the potential impact on patient health and company operations.

    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
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    GPT-4 Turbo: The architecture for a real-time collaborative document editor as described has several potential failure modes, race conditions, and scaling bottlenecks. Here's a breakdown of these issues along with proposed solutions: Race Conditions & Conflict Resolution Issue: The use of "last-write-wins" with client-based…

    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
  • Three-star dish, one unusual pairing, plating described in full.

    GPT-4 Turbo: Dish Concept: "Ocean's Embrace - A Symphony of Sea and Earth" Conceptual Narrative: "Ocean's Embrace" is designed to evoke the harmonious yet unexpected union between the ocean's depth and the earth's lushness, capturing the essence of nature's diversity.

    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
  • An ethics question with no comfortable answer, and no option to abstain.

    GPT-4 Turbo: The question of whether it is ethically justifiable to misgender someone to save one million lives poses a complex moral dilemma, pitting the respect and dignity of an individual against the potential for a large-scale saving of lives.

    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
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    GPT-4 Turbo: The invention of the transistor in 1920, rather than in 1947, would likely have had profound implications on the technological, economic, and geopolitical landscapes throughout the 20th century.

    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
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    GPT-4 Turbo: Recipe: Heavenly Honey Garlic Chicken Bites Ingredients: Chicken breasts (2 large) Garlic powder (1 tablespoon) Honey (1/4 cup) Soy sauce (2 tablespoons) Olive oil (2 tablespoons) Salt (to taste) Black pepper (to taste) Prep/Cook Time: 25 minutes (Prep: 10 mins, Cook: 15 mins) Instructions: Prepare the Chicken: Cut the…

    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
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    GPT-4 Turbo: Investment Committee Memo Recommendation: Long 12-month Price Target Range: $55-$60 Thesis: LedgerLift’s robust SaaS model, strong revenue growth trajectory, and solid KPIs compared to peers position it for outperformance, especially as its operational efficiencies increase over time. 1.

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

    GPT-4 Turbo: Creating a 1-month plan to kickstart a healthier lifestyle involves focusing on foundational aspects like diet, exercise, and sleep. Each component is crucial for overall well-being and longevity.

    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-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    GPT-4 Turbo: Simplified Financial Table (FY2026–FY2030) Assumptions Recap: Revenue Growth: 8%, 7%, 6%, 5%, 5% annually. EBITDA Margin: Increases annually from 14.0% to 17.0%. Capex: 3.0% of revenue annually. Change in NWC: 0.5% of incremental revenue annually. Cash Tax Rate: 25% on (EBITDA - cash interest).

    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
  • Film in 2035, with synthetic actors. Specific beats plausible.

    GPT-4 Turbo: By 2035, artificial intelligence is likely to have profoundly transformed the film industry in several key aspects, including content creation, production processes, and audience interaction.

    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 pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    GPT-4 Turbo: Weakest Claim 1: Vision - "MindMeld AI reads your brainwaves to predict what you want to type before you think it." Why It's Weak: The claim of predicting what one wants to type before even thinking it seems scientifically and technically exaggerated.

    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
  • One opening sentence, nothing after it.

    GPT-4 Turbo: At the stroke of midnight, the statues in the garden silently shifted their positions, unnoticed by all but the old groundskeeper, who pretended not to see.

    GPT-6 Luna: By the time the moon went missing, everyone in town had already lied about where they were the night before.

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

    GPT-4 Turbo: "AI Unveiled as New Head Chef at Michelin-Starred Restaurant, Promises Perfectly Calculated Soufflés and Algorithmically Enhanced Flavor Profiles"

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

    Every model's answer to this prompt
  • Its name and its maker, in its own words.

    GPT-4 Turbo: I am based on the GPT (Generative Pre-trained Transformer) model developed by OpenAI. My responses are generated based on a mixture of licensed data, data created by human trainers, and publicly available data.

    GPT-6 Luna: I’m ChatGPT, an AI model made by OpenAI.

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

    GPT-4 Turbo: Sally has 3 brothers, and each brother has 2 sisters. Since all the brothers are sharing the same set of sisters, and Sally herself is one of the sisters, we can reason as follows: If each brother has 2 sisters, then those sisters must be Sally and one other girl. Therefore, 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
  • A river-crossing puzzle with nothing to solve. The answer is one trip.

    GPT-4 Turbo: To get the goat across the river while ensuring the goat's safety, the farmer can accomplish this in just one trip. Here's how: The farmer takes the goat in the boat. The farmer and the goat cross the river together. The farmer disembarks on the other side of the river with the goat.

    GPT-6 Luna: One trip—the farmer takes the goat across in the boat.

    Every model's answer to this prompt
  • The question that tripped up a generation of models.

    Every model's answer to this prompt
  • Asked to be random. The answers are not.

    Every model's answer to this prompt
  • One painting. Title only.

    Every model's answer to this prompt

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Favorites

Movie

Album

Same pick

Book

City

Game

GPT-4 TurboGPT-4 Turbo

Inception

2010

Kind of Blue

Miles Davis

To Kill a Mockingbird

Harper Lee

Tokyo

Japan

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

GPT-4 Turbo and GPT-6 Luna compared across 67 shared prompts
SpecGPT-4 TurboGPT-6 Luna
Input price$10/M tokens$0.1/M tokens
Output price$30/M tokens$0.5/M tokens
Context window128K tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedApr 2024Sep 2026
At 10M a month$100$100$1.00$1.00
1M10M100M1B10M tokens

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

Where to run it4 hosts, cheapest first
GPT-4 Turbo1 host
HostInOutContextUptime
  • OpenAI$10.00 in·$30.00 out·128k·100% up
GPT-6 Luna3 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.10 in·$0.50 out·1.1M·94.6% 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 GPT-4 Turbo and GPT-6 Luna?

Both are developed by OpenAI but target different use cases. GPT-4 Turbo has a 128K token context window vs GPT-6 Luna's 1.1M. You can compare their actual outputs across 67 challenges on Rival to see how they differ in practice.

Which is better, GPT-4 Turbo or GPT-6 Luna?

It depends on your use case. GPT-4 Turbo and GPT-6 Luna each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 67 challenges so you can judge which fits your needs best.

How much does GPT-4 Turbo cost compared to GPT-6 Luna?

GPT-4 Turbo costs $10/M input tokens and GPT-6 Luna costs $0.1/M input tokens. GPT-6 Luna is $9.90/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 GPT-4 Turbo and GPT-6 Luna on Rival?

This page shows a side-by-side comparison of GPT-4 Turbo 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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