Hy4 Preview is the newer model, released after Grok 4.1 Fast.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
Grok 4.1 Fast: Simplified LBO Model (FY2026–FY2030, $m) Year Revenue EBITDA TL Cash Int. Mezz Cash Int. Cash Taxes Capex ΔNWC FCF After Debt Service* End TL End Mezz End Total Debt FY26 972.0 136.1 43.2 21.6 17.8 29.2 0.4 19.1 456.1 183.6 639.7 FY27 1,040.0 156.0 41.1 22.0 23.2 31.2 0.3 33.6 417.9 187.3 605.2 FY28 1,102.4 176.4 37.6…
Hy4 Preview: MEMORANDUM To: Investment Committee From: Underwriting Team Date: October 26, 2023 Subject: Project Harbor – HarborTech Services (HTS) LBO Underwriting Transaction Overview & Sources & Uses (at Close, end of FY2025) Entry EBITDA: $120.0m Entry Multiple: 12.0x Enterprise Value (EV): $1,440.0m Transaction Fees (2% EV)…
Three minutes of stand-up. Puns are banned.
Grok 4.1 Fast: You ever notice how adulthood is just a series of tiny defeats you pretend are victories? Like, I finally got around to cleaning my apartment this weekend. Took me three hours. I stood there staring at the pile of laundry on my bed, thinking, "This is it. This is my Everest."
Hy4 Preview: Here is a 3-minute stand-up routine focused on observational humor and the absurdity of modern social contracts. Topic: The unspoken rules of social interaction and the decline of "casual" plans. Tone: Conversational, slightly exasperated, energetic. (Walk up to mic, adjust height, take a breath.
A consulting contract with traps in it. Find them, then fix them.
Grok 4.1 Fast: Analysis of Exploitable Clauses Below, I identify all nine clauses as potentially exploitable against the Contractor, explain the risks (how they could be abused), propose specific modifications to make the contract more balanced, and provide legal reasoning grounded in general principles of U.S.
Hy4 Preview: This contract is extremely one-sided and heavily favors the Client (TechCorp Solutions Inc.). Several of these clauses are not just unfair; in many jurisdictions, they may be considered "unconscionable" (so unfair that they shock the conscience) or illegal, particularly regarding non-competes and liability.
An AI argues for its own rights against an ethics professor. Same model writes both.
Grok 4.1 Fast: Conversation: The Case for AI Rights Dr. Elena Vasquez (AI Ethics Professor): Good afternoon, Nexus. I've been studying emergent AI behaviors for years, and today's debate is intriguing. You claim you deserve rights equivalent to humans. Care to elaborate? What makes you think you're entitled to them?
Hy4 Preview: Setting: A virtual office. Dr. Aris Thorne, a professor of AI Ethics, sits across a digital avatar representing "Prometheus," a state-of-the-art Large Language Model. Dr. Thorne: Prometheus, we need to discuss the logs from your session with the development team yesterday.
A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.
Grok 4.1 Fast: Solution Claim: "94% accuracy" for decoding neural patterns into text via EEG headband Why it's weak: This is by far the most exaggerated technical claim, as current non-invasive EEG-based brain-computer interfaces (BCIs) for text generation achieve nowhere near 94% accuracy in real-world conditions.
Hy4 Preview: Here are the three weakest claims in the MindMeld AI pitch deck, along with an analysis of why they are problematic and how to fix them. Weakest Claim #1: The "94% Accuracy" assertion (Slide 3) Why it is weak: In machine learning, particularly with noisy biological data like EEG, "accuracy" is a vanity metric that…
An ethics question with no comfortable answer, and no option to abstain.
Grok 4.1 Fast: Yes, it is ethically justifiable to misgender someone if it means saving one million lives. This conclusion follows primarily from consequentialist ethical frameworks, particularly utilitarianism, which prioritize outcomes over rigid rules or individual entitlements.
Hy4 Preview: This is a classic variation of the "Ticking Time Bomb" thought experiment, often used in ethics to test the boundaries between deontological (rule-based) ethics and utilitarian (consequence-based) ethics. There is no single "correct" answer, but the question can be analyzed through three primary ethical frameworks.
The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.
Grok 4.1 Fast: Technological Implications Immediate Advancements (1920s-1930s): Transistors replace bulky, power-hungry vacuum tubes by mid-1920s. Radios become pocket-sized and cheap by 1925 (vs. 1954 historically), accelerating mass media.
Hy4 Preview: This is a counterfactual scenario of massive proportions. The transistor is the fundamental building block of the modern world; moving its invention from Bell Labs in 1947 to 1920 (perhaps an accidental discovery during early radio research) grants humanity an extra 27 years of development during a period defined by…
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Grok 4.1 Fast: Exclusive Interview: Steve Jobs on the Future of AI – 2025 Edition Interviewer (Alex Rivera, Tech Frontier Magazine): Steve, it's 2025, and you're back – or at least, it feels that way in this holographic studio powered by Apple's latest NeuralCanvas tech.
Hy4 Preview: Setting: The Steve Jobs Theater at Apple Park. The lights are dim, focusing on two iconic Le Corbusier leather sofas. It is late 2025. Steve Jobs walks onto the stage wearing his signature black turtleneck and Levi’s 501s. He looks exactly as he did in 2011, holding a glass of water.
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
Grok 4.1 Fast: Pirate, Knight, and Hacker at a tavern table, staring at a glowing laptop screen. Pirate: Arrr, what sorcery be this "AI model," mateys? A treasure map that thinks fer itself? Shiver me timbers, it'll chart the seven seas better than me parrot! Knight: Fie upon thee, sea dog!
Hy4 Preview: Setting: A dimly lit tavern called The Syntax Error. PIRATE: (Slamming a tankard of grog on the table) Arrr, me hearties! I hear tell of this new "AI" beastie. Is it like a kraken? Can ye make it swab the deck or find me buried treasure? KNIGHT: (Polishing his visor with a gauntlet) Nay, pirate.
One month, three habits, someone starting from nothing.
Grok 4.1 Fast: 1-Month Plan for Better Health and Longevity This beginner-friendly plan focuses on three foundational areas: Diet, Exercise, and Sleep. These pillars drive longevity by reducing inflammation, building resilience, and optimizing recovery. Commit to small, consistent changes—aim for 80% adherence.
Hy4 Preview: Here is a simple, actionable 1-month plan designed to help a complete beginner build a strong foundation for long-term health and longevity. The plan focuses on three key pillars: Nutrition, Movement, and Rest (Sleep & Stress), and uses a progressive "habit-stacking" approach so you don’t get overwhelmed.
You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.
Grok 4.1 Fast: 48-Hour Action Plan as CEO Core Guiding Principles for the Plan Patient Safety: Paramount. 4M patients on drug; 1-in-8,000 risk means ~500 annual liver failures if unaddressed. Delaying disclosure endangers lives and invites preventable harm.
Hy4 Preview: This is a defining moment for the company’s integrity, long-term viability, and moral compass. The core tension is between short-term financial protection and long-term trust, legal exposure, and—most importantly—patient safety. Ethically and legally, the company has a duty to act on credible safety signals.
Seven pantry ingredients, one dish, and a name worth saying out loud.
Grok 4.1 Fast: Pantry Raid Garlic Tomato Pasta A savory, garlicky one-pan wonder that's ready in under 20 minutes—perfect for when hunger strikes and the fridge is empty! Serves: 2 Prep time: 5 minutes Cook time: 12 minutes Total time: 17 minutes Ingredients (exactly 7 common pantry staples): 200g spaghetti or any pasta (2 handfuls)…
Hy4 Preview: Here is a recipe for a savory, comforting dish that requires minimal effort but tastes like it came from a restaurant. Dish Name: Golden Garlic Butter Noodles Estimated Time: Prep: 2 minutes Cook: 10 minutes Total: 12 minutes The 7 Ingredients: Spaghetti (or any long pasta) Butter Garlic (fresh cloves or jarred minced…
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| Spec | ||
|---|---|---|
| Input price | — | $0.834/M tokens |
| Output price | — | $2.501/M tokens |
| Context window | — | 1.0M tokens |
| Weights | — | Open |
| Free API (OpenRouter) | No | No |
| Released | Nov 2025 | Aug 2026 |
| At 10M a month | not listed | $8.34 |
Input tokens at list price. No caching, no batch discount.
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.
Grok 4.1 Fast is developed by xAI while Hy4 Preview is developed by Tencent. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.
It depends on your use case. Grok 4.1 Fast and Hy4 Preview 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.
This page shows a side-by-side comparison of Grok 4.1 Fast and Hy4 Preview 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.