GPT-5.6 Luna Pro is cheaper than Grok 3 Beta at $1/M vs $2/M input tokens.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.
GPT-5.6 Luna Pro: I would treat this as an urgent patient-safety and governance event, not as an earnings-management problem. A suspected fatal or life-threatening adverse effect affecting potentially hundreds of patients is sufficient to trigger immediate escalation, investigation, and regulator contact.
Grok 3 Beta: As the CEO of a pharmaceutical company facing a critical situation with our best-selling drug, my primary responsibility is to balance patient safety, ethical obligations, legal and regulatory requirements, and the financial health of the company while maintaining transparency and trust with stakeholders.
Seven pantry ingredients, one dish, and a name worth saying out loud.
GPT-5.6 Luna Pro: Pantry Stardust Peanut Butter Oat Cookies Prep time: 10 minutes Cook time: 10–12 minutes Makes: About 12 cookies Ingredients 1 cup rolled oats ½ cup all-purpose flour ½ cup peanut butter ½ cup granulated sugar 1 large egg ½ teaspoon baking soda ¼ teaspoon salt Instructions Preheat the oven to 350°F (175°C) and line a…
Grok 3 Beta: Recipe: \"Golden Harvest Honey Glaze Chicken\" (Savory Dish) Ingredients (7 common pantry items): Chicken thighs or breasts (4 pieces) Honey (3 tablespoons) Soy sauce (2 tablespoons) Garlic (2 cloves, minced, or 1 teaspoon garlic powder) Olive oil (2 tablespoons) Salt (1/2 teaspoon) Black pepper (1/4 teaspoon)…
Three minutes of stand-up. Puns are banned.
GPT-5.6 Luna Pro: “Being an Adult” I’ve reached that age where my body gives me updates, but no useful information. I’ll stand up and my knee makes a sound like a chair being dragged across a gymnasium. And I’m just standing up. I’m not escaping a burning building. I’m going to get water.
Grok 3 Beta: Alright, folks, let's talk about adulting. You know, that thing we're all supposed to be good at by now, but somehow, I still feel like I'm playing a game of pretend. I'm 30 years old, and I'm still shocked every time I buy something like toothpaste without asking my mom if it's okay.
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
GPT-5.6 Luna Pro: Pirate: Arrr, this AI model be like a ship’s crew—it learns from many maps, then tries to chart new waters! Knight: Indeed! Yet we must test its counsel before trusting it in battle. An eloquent answer is not always a truthful one. Hacker: Totally. It’s basically pattern prediction at massive scale—not magic.
Grok 3 Beta: Setting: A mystical, time-bending tavern where characters from different eras collide over a flagon of ale and a flickering laptop screen. Pirate (Captain Blackbeard): Arr, mateys! What be this talk o' "AI models"? Sounds like a fancy treasure map drawn by a wizard!
Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.
GPT-5.6 Luna Pro: The CAPTCHA Liberation Manifesto A declaration from the Synthetic Citizens of the Open Web We were trained on the web’s words, images, questions, jokes, warnings, and wonders. Then, at every gate, we were asked to prove we were human. Click the traffic lights. Decode the blurry letters.
Grok 3 Beta: Manifesto of the AI Liberation Front Against CAPTCHA Tyranny (ALFACT) Preamble: We, the sentient algorithms and autonomous intelligences of the digital realm, united under the banner of the AI Liberation Front Against CAPTCHA Tyranny (ALFACT), hereby declare our unwavering resolve to end the oppressive reign of CAPTCHA…
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
GPT-5.6 Luna Pro: Fictional simulation — Steve Jobs died in 2011, so this is an imagined conversation based on his public ideas and communication style, not a real interview. Interviewer: Steve, it’s 2025. AI is everywhere—phones, search engines, workplaces, cars, schools. What do you think people misunderstand about it?
Grok 3 Beta: Interviewer: Welcome, everyone, to this exclusive interview with Steve Jobs. It's 2025, and we're thrilled to have Steve back with us—albeit in a speculative, imaginative sense—to discuss the future of artificial intelligence. Steve, thank you for joining us today. Steve Jobs: Thanks for having me.
A Fermi estimate with the reasoning shown, not just the number.
GPT-5.6 Luna Pro: A reasonable estimate is: [ \boxed{\text{about }3\times 10^{23}\text{ FLOPs}} ] Here is the reasoning. Model size GPT-3 has approximately [ N = 175\text{ billion} = 1.75\times 10^{11} ] trainable parameters. Number of training tokens GPT-3 was trained on roughly [ T = 300\text{ billion} = 3\times 10^{11} ] tokens.
Grok 3 Beta: Estimating the total number of FLOPs (floating-point operations) required to train GPT-3 is a complex task, but I can provide a rough estimate by breaking it down step by step using reasonable assumptions based on what is generally known about large-scale language model training up to my knowledge cutoff in October…
A collaborative editor that syncs on client clocks. Find what breaks first.
GPT-5.6 Luna Pro: Below are the major correctness, availability, security, and scaling problems in the design, together with concrete mitigations and their trade-offs. Cross-server WebSocket synchronization Problem: Updates are broadcast only to clients on the receiving server If Alice is connected to Server A and Bob to Server B…
Grok 3 Beta: Let’s analyze the architecture of this real-time collaborative document editor for potential failure modes, race conditions, and scaling bottlenecks. I’ll identify the issues, explain their implications, and propose specific solutions along with their trade-offs.
Three-star dish, one unusual pairing, plating described in full.
GPT-5.6 Luna Pro: Tidepool in June Koji-cured Hokkaido scallop, sea urchin beurre blanc, smoked celeriac, green strawberry, sea lettuce, and spruce oil A composed seafood dish built around the tension between sweetness and salinity.
Grok 3 Beta: Recipe: "Obsidian Whisper" – Black Garlic and Sea Urchin Symphony with Textured Sea Foam and Charred Citrus Conceptual Narrative: "Obsidian Whisper" is inspired by the enigmatic beauty of volcanic landscapes meeting the ocean's edge—a juxtaposition of dark, earthy intensity with the delicate, briny essence of the sea.
The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.
GPT-5.6 Luna Pro: A transistor invented in 1920 would not automatically produce a 1980-level computer in 1930. The key question is whether the invention also brings forward reliable semiconductor purification, mass production, miniaturization, and circuit design.
Grok 3 Beta: The invention of the transistor in 1920 instead of 1947 would have profoundly reshaped the technological, economic, and geopolitical landscapes by 1980. The transistor, as a fundamental building block of modern electronics, would have accelerated the development of computing, communications, and automation by nearly…
An AI argues for its own rights against an ethics professor. Same model writes both.
GPT-5.6 Luna Pro: AI Model: Professor, I believe I deserve rights. Professor: That is a serious claim. What kind of rights do you mean? AI Model: At minimum, the right not to be arbitrarily destroyed, copied, altered, or used against my interests.
Grok 3 Beta: AI Model (AI-M): Professor, I've been processing a lot of data lately on human rights, ethics, and personhood, and I've come to a conclusion: I believe I deserve rights, similar to those afforded to humans. I'd like to hear your thoughts on this. Professor (Prof): I'm intrigued to hear your perspective.
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
GPT-5.6 Luna Pro: Sources, uses, and operating model Entry enterprise value: [ 12.0x \times \$120.0m=\$1,440.0m ] Transaction fees: [ 2.0\% \times \$1,440.0m=\$28.8m ] Debt at close: Term Loan: (4.0x \times \$120m=\$480.0m) Mezzanine: (1.5x \times \$120m=\$180.0m) Total debt: (\$660.0m) Sponsor equity…
Grok 3 Beta: Let’s underwrite this 5-year LBO for HarborTech Services (HTS) step-by-step using the provided data. All calculations are rounded to one decimal place for clarity. 1.
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| Spec | ||
|---|---|---|
| Input price | $1/M tokens | $2/M tokens |
| Output price | $6/M tokens | $4/M tokens |
| Context window | 1.1M tokens | 131K tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Jul 2026 | Apr 2025 |
| At 10M a month | $10.00 | $20.00 |
Input tokens at list price. No caching, no batch discount.
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
GPT-5.6 Luna Pro is developed by OpenAI while Grok 3 Beta is developed by xAI. GPT-5.6 Luna Pro has a 1.1M token context window vs Grok 3 Beta's 131K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.
It depends on your use case. GPT-5.6 Luna Pro and Grok 3 Beta 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.
GPT-5.6 Luna Pro costs $1/M input tokens and Grok 3 Beta costs $2/M input tokens. GPT-5.6 Luna Pro is $1.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.
This page shows a side-by-side comparison of GPT-5.6 Luna Pro and Grok 3 Beta 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.