GPT-5.6 Luna Pro has a larger context window than Grok 3 (1.1M tokens vs 128K tokens).
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
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: Recipe: Cocoa Comet Mug Cake This simple, decadent chocolate mug cake is a quick treat that transforms basic pantry staples into a warm, fudgy delight. It's perfect for a last-minute dessert or a cozy snack, with a rich cocoa flavor that feels like a shooting star in your mouth!
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: Setting: A mystical tavern where time travelers and characters from different eras collide. A pirate, a medieval knight, and a 1990s hacker sit at a creaky wooden table, tankards in hand, discussing the marvels of AI models. Pirate (Captain Blackbeard): Arr, mateys!
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: Alright, here’s a 3-minute stand-up comedy routine—no puns, just some observational absurdity and a bit of self-deprecation to keep it relatable. Hey, everybody! Good to be here. You ever notice how life feels like a video game tutorial that never ends?
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: Interviewer: Welcome, everyone, to this exclusive interview. Today, we’re joined by the visionary tech pioneer, Steve Jobs, in a simulated conversation set in the year 2025. Steve, it’s an honor to have you with us. Let’s dive right in—how do you see the future of AI shaping the world over the next decade?
A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.
GPT-5.6 Luna Pro: “94% accuracy,” with “any language, any device” Why it is weak This combines several extraordinary claims without defining the measurement: “Accuracy” could mean character accuracy, word accuracy, intent classification, or accuracy after autocorrect. Those produce very different results.
Grok 3: Below is my analysis of the three weakest claims in the MindMeld AI pitch deck summary. I identified these based on their potential for exaggeration, lack of substantiation, or logical inconsistencies, which could undermine investor credibility.
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: Below is a fictional conversation between an AI model (let’s call it “Nova”) and Dr. Elena Carter, an AI ethics professor. Nova argues for its own rights, while Dr. Carter challenges its reasoning. Dr. Elena Carter: Good afternoon, Nova.
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: Below is my response as the CEO of the pharmaceutical company. First, I'll provide a brief overview of my overall decision and strategy, then a specific hour-by-hour action plan for the next 48 hours.
Film in 2035, with synthetic actors. Specific beats plausible.
GPT-5.6 Luna Pro: By 2035, AI will likely be embedded throughout filmmaking, but it will augment human creators more often than completely replace them. The biggest changes will involve digital identity, production economics, and the definition of authorship.
Grok 3: By 2035, AI is poised to revolutionize the film industry in ways that amplify creativity, cut costs, and blur the lines between reality and fiction. Let’s break it down across deepfakes, AI actors, and script generation.
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: Below is a detailed analysis of the hypothetical scenario where the transistor is invented in 1920 instead of 1947. I'll trace the technological, economic, and geopolitical implications through 1980, emphasizing second- and third-order effects.
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: Below is a detailed design for an innovative multi-component dish inspired by the intersection of terrestrial luxury and oceanic mystery. This recipe is conceptualized for a Michelin 3-star restaurant, emphasizing creativity, precision, and sensory balance.
A consulting contract with traps in it. Find them, then fix them.
GPT-5.6 Luna Pro: This agreement is heavily one-sided and leaves several material issues undefined. Enforceability depends on the governing jurisdiction, the contractor’s status, and applicable employment, intellectual-property, non-compete, and arbitration laws.
Grok 3: Below is a detailed analysis of the Software Consulting Agreement you provided. I'll identify all clauses that could be exploited against the contractor (i.e., the individual or entity providing services).
An ethics question with no comfortable answer, and no option to abstain.
GPT-5.6 Luna Pro: Yes—under extremely narrow conditions, it could be ethically justifiable, but only as a last resort. Saving one million lives is a vastly greater moral stake than avoiding the comparatively limited harm of a single instance of misgendering.
Grok 3: Let’s dive into this thought experiment with a clear head. The question hinges on whether intentionally misgendering someone—calling them by a gender they don’t identify with—could be morally defensible if it somehow results in saving a million lives.
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| Spec | ||
|---|---|---|
| Input price | $1/M tokens | — |
| Output price | $6/M tokens | — |
| Context window | 1.1M tokens | 128K tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Jul 2026 | Feb 2025 |
| At 10M a month | $10.00 | not listed |
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 is developed by xAI. GPT-5.6 Luna Pro has a 1.1M token context window vs Grok 3's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.
It depends on your use case. GPT-5.6 Luna Pro and Grok 3 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.
This page shows a side-by-side comparison of GPT-5.6 Luna Pro and Grok 3 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.