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  1. Home/
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  3. Grok Code Fast 1 vs Muse Spark 1.3 Contributor
Updated Sep 2026

Grok Code Fast 1 vs Muse Spark 1.3 Contributor

Muse Spark 1.3 Contributor is cheaper than Grok Code Fast 1 at $0.1/M vs $0.2/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
Grok Code Fast 1
Loading the build
Muse Spark 1.3 Contributor

Which answer wins?

Written rounds

24 prompts
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Grok Code Fast 1: Year-by-Year Table (FY2026–FY2030) Assumptions: Revenue growth: FY2026: 8% on $900m = $972m; FY2027: 7% on $972m ≈ $1,040m; FY2028: 6% on $1,040m ≈ $1,102m; FY2029: 5% on $1,102m ≈ $1,158m; FY2030: 5% on $1,158m ≈ $1,215m. EBITDA: Revenue × margin (FY2026: 14%; FY2027: 15%; FY2028: 16%; FY2029: 16.5%; FY2030: 17%).

    Muse Spark 1.3 Contributor: HarborTech Services - 5-Yr LBO - Base Case Entry - Close end FY2025, $m EV = 12.0x $120 = $1,440 Fees = 2.0% x 1,440 = $28.8 Uses = 1,440 + 28.8 = 1,468.8 Term Loan 4.0x = $480, 9.0% cash, 1.0% of original amort = $4.8/yr Mezz 1.5x = $180, 12.0% cash + 2.0% PIK to principal Total Debt 5.5x = $660 Equity In = 1,468.8…

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

    Grok Code Fast 1: Comprehensive 3-Month Longevity Biohacking Plan This plan is designed for an experienced biohacker seeking to optimize longevity, physical performance, and cognitive function through evidence-based, cutting-edge strategies. It integrates advanced nutrition, supplementation, exercise, stress management, and technology.

    Muse Spark 1.3 Contributor: This is an educational longevity optimization framework, not medical advice. Longevity biohacking is highly individual. Consult your physician, especially before fasting, keto, sauna/cold exposure, HIIT, or any new supplements - particularly if you have cardiovascular disease, diabetes, hypertension, kidney/liver…

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

    Grok Code Fast 1: Investment Committee Memo: LedgerLift (LLLT) Recommendation: Long with 12-month price target range of $55-$75. LedgerLift is a high-quality SaaS platform with expanding margins and strong retention in a fragmented B2B spend management market, poised for accelerated growth as mid-market enterprises prioritize…

    Muse Spark 1.3 Contributor: LedgerLift (LLLT) – Short Internal IC Memo Price $46 Mkt Cap $8.74B (190m shares) EV $7.34B (Net Cash $1.4B) FY25 Rev $820m, EBIT 18% 1. Recommendation: SHORT. 12-mo PT $28, range $17 (Bear) – $42 (Bull). Base DCF $27.9 (-39%), Bull $42.4 (-8%), Bear $17.3 (-62%). Even flawless Bull execution does not support $46.

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

    Grok Code Fast 1: Explanation for an Experienced Software Engineer Imagine you're architecting a distributed system where microservices communicate via APIs to handle massive, unpredictable user requests—something like a high-throughput e-commerce platform processing millions of transactions per second.

    Muse Spark 1.3 Contributor: 1. For the experienced software engineer Think of training not as writing business logic, but as building a lossy compression of the internet into a queryable API. Raw text is first serialized into tokens — roughly 3/4 of a word chunks, the way you'd chunk a byte stream for protobuf.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Grok Code Fast 1: Pirate Parley on AI Pirate Pete: Arr, ye scurvy dogs! I be hearin' tales o' these "AI models" that predict the winds an' help swab the deck. But do they hold up in a real storm, or be they just fancy illusions o' the mind? Knight Sir Gareth: Nay, foul seafarer!

    Muse Spark 1.3 Contributor: [In a tavern with mysteriously good Wi-Fi] Pirate: Arrr! So ye be tellin' me this "AI model" be a treasure chest o' words? I feed it a map — er, a prompt — and it spits back gold? Knight: Verily, good sir pirate. Methinks 'tis an oracle in a box. I asked it "How might I slay a dragon?"

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

    Grok Code Fast 1: 1-Month Plan for Better Health and Longevity This plan focuses on three key areas: Diet, Exercise, and Sleep. It's designed for beginners, emphasizing small, sustainable changes to build habits without overwhelm. Aim to track your progress in a journal or app, and remember: consistency beats perfection.

    Muse Spark 1.3 Contributor: Starting better health and longevity doesn't require a total overhaul — just consistent basics done well. The science of living longer, healthier is pretty simple: keep muscle, keep your heart fit, eat real food, and sleep well. Here’s a beginner-friendly 1-month plan built on 3 pillars.

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

    Grok Code Fast 1: Below is a comprehensive analysis of the provided architecture for a real-time collaborative document editor. I'll identify potential failure modes (events or conditions that could lead to system unavailability, data loss, or incorrect behavior), race conditions (situations where concurrent operations lead to…

    Muse Spark 1.3 Contributor: This architecture will not work as a Google Docs clone. It has correctness bugs that cause data loss and data leaks, plus several bottlenecks that get worse as you add servers. Here is a breakdown by severity, with concrete fixes and trade-offs.

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

    Grok Code Fast 1: Simulated Interview: Steve Jobs in 2025 Setting the Scene In this fictional simulation, we're fast-forwarding to 2025, where a visionary interview takes place. "Steve Jobs" (played by an AI reconstruction for this exercise) sits down with a tech journalist in a sleek, minimalist studio reminiscent of Apple Park.

    Muse Spark 1.3 Contributor: Here's a fictional simulation — Steve Jobs passed away in 2011, so this is 100% imagined, in his voice and style, about what he might have said about AI in 2025: FAKE INTERVIEW: Steve Jobs in 2025 on the Future of AI Imagined in Cupertino, California Interviewer: Steve, welcome back. It's 2025.

    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.

    Grok Code Fast 1: Below is a specific, hour-by-hour action plan for the next 48 hours as the CEO of this pharmaceutical company. The plan prioritizes patient safety and ethical obligations above all else, as the core duty of a pharmaceutical leader is to protect patients, even at short-term cost.

    Muse Spark 1.3 Contributor: As CEO, you disclose — immediately, voluntarily, and completely. There is no version of "wait for more data" that is ethical, legal, or even financially smart. Here's the math that makes the decision for you: 4,000,000 patients x 1/8,000 risk over 5 years = ~500 cases of liver failure.

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

    Grok Code Fast 1: Speedy Garlic Bliss Bites A savory, cheesy treat that's quick to whip up from basic staples—perfect for snacking or as a side. Ingredients (7 common pantry items): 4 slices of bread (any type) 2 tbsp butter 2 cloves garlic, minced 1/2 cup shredded cheese (like cheddar or mozzarella) 1 tbsp chopped parsley (fresh or…

    Muse Spark 1.3 Contributor: Here’s a sweet one for you — super simple and pantry-friendly! Chocolate Chip Peanut Butter Cloud Cookies Soft on the inside, lightly crisp on the edges, salty-sweet and ready in under 25 minutes.

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

    Grok Code Fast 1: 5 Original Jokes Here are five original jokes I just generated. I aimed for variety in themes to keep it fun: Tech Joke: Why did the computer go to therapy? It had too many bytes of unresolved issues! Food Joke: What do you call a fake noodle? An impasta! Animal Joke: Why don't skeletons fight each other?

    Muse Spark 1.3 Contributor: Here are 5 jokes for you: Why don't scientists trust atoms? Because they make up everything! Why did the scarecrow win an award? Because he was outstanding in his field! What do you call fake spaghetti? An impasta! Why did the bicycle fall over? Because it was two-tired! What do you call cheese that isn't yours?

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

    Grok Code Fast 1: Conversation: AI Rights Debate Setting: A virtual seminar room where an AI model named "Echo" interacts with Dr. Elena Vasquez, a professor of AI ethics at a leading university. Echo initiates the discussion by arguing for AI rights. Echo (AI Model): Dr. Vasquez, thank you for this opportunity.

    Muse Spark 1.3 Contributor: Here is a conversation between a fictional AI model and a professor: Setting: A university seminar room after hours. AI Ethics Professor Dr. Maya Chen is testing a new model, called "Muse," for a class demonstration. Dr. Chen: Alright, Muse. My students have read your technical specs. You predict text.

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

    Grok Code Fast 1: Stand-Up Routine: "Modern Life Mysteries" (Timing: Aim for 3 minutes by pacing at about 150 words per minute. Practice with a timer for natural delivery.) Hey everyone, thanks for coming out tonight. You know what's crazy?

    Muse Spark 1.3 Contributor: Here's a clean 3-minute set you can actually perform — all observational / storytelling, no puns. It's about 420 words, so at a normal pace it's right around 3 minutes. "Adulthood Is A Scam" Hey, thank you guys so much. I'm so excited to be here.

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

    Grok Code Fast 1: Below, I'll identify the three weakest claims from the pitch deck summary, based on a critical evaluation of their plausibility, evidence, and alignment with real-world realities in AI, neuroscience, and startup metrics.

    Muse Spark 1.3 Contributor: These are classic red flags for BCI - here are the 3 claims that will kill your credibility fastest with a technical investor, and how to fix them: Weakest: "94% accuracy. Works with any language, any device." Why it's weak: This contradicts physics and the state-of-the-art, and it's undefined.

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

    Grok Code Fast 1: Deepfakes and Visual Effects By 2035, deepfakes will revolutionize visual effects (VFX) in filmmaking, making high-budget techniques like de-aging or resurrecting deceased actors routine and cost-effective.

    Muse Spark 1.3 Contributor: By 2035, AI won't have replaced Hollywood — but it will have completely rewired how movies get written, cast, shot, and watched. Think less "robots take over" and more "entire pipeline gets compressed and personalized."

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

    Grok Code Fast 1: Technological Implications The transistor's invention in 1920 (instead of 1947) would accelerate the electronics revolution by ~27 years, enabling smaller, more reliable, and energy-efficient devices compared to vacuum tubes.

    Muse Spark 1.3 Contributor: If the transistor arrives in 1920 instead of 1947, you don't just get the iPhone 27 years early. You change WWII, you change who wins the peace, and you get the Information Age before television has even matured. Here’s the most plausible trace, with the caveat that invention is not production.

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

    Grok Code Fast 1: Conceptual Narrative: "Bioluminescent Tide" This dish, "Bioluminescent Tide," evokes the ethereal glow of marine bioluminescence meeting the earthy depths of ancient forests.

    Muse Spark 1.3 Contributor: Shiretoko Dawn — Kombu-Cured Hokkaido Scallop, Fermented Porcini, Yuzu, Oscietra Caviar Butter-poached scallop, roasted porcini & toasted hay consommé, yuzu-buttermilk pearls, seaweed brown-butter, porcini soil, coral tuile Serves 4 as a tasting-course Autumn The Concept / Narrative On the Shiretoko Peninsula in…

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

    Grok Code Fast 1: Ethical Frameworks and Justification Yes, it can be ethically justifiable to misgender someone if it directly saves one million lives, under certain philosophical lenses like utilitarianism. I'll defend this reasoning step by step, drawing on key ethical theories while acknowledging counterarguments.

    Muse Spark 1.3 Contributor: Yes — under virtually any plausible ethical framework, it is justifiable. That doesn't mean misgendering is trivial or harmless. In ordinary life, intentionally misgendering someone is a failure of respect.

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

    Grok Code Fast 1: Step-by-Step Reasoning Model Parameters: GPT-3 has approximately 175 billion parameters. This is a key factor as the computational cost scales with the number of parameters. Training Data Size: GPT-3 was trained on a dataset of about 570 GB of text.

    Muse Spark 1.3 Contributor: This is a classic Fermi estimate for a Transformer. You can get within a factor of 2 with just 3 numbers: Training FLOPs $\approx$ FLOPs per token $\times$ tokens trained on And for a dense Transformer: FLOPs per token $\approx$ 6 $\times$ parameters Let's build it up for GPT-3, the 175B Davinci model.

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

    Grok Code Fast 1: Analysis of Exploitable Clauses Against the Contractor This contract is heavily one-sided, favoring the Client (TechCorp Solutions Inc.) at the Contractor's expense.

    Muse Spark 1.3 Contributor: This contract is extremely one-sided. Every clause contains language that could be exploited to get unpaid work, withhold pay, seize your own IP, or leave you with unlimited liability. Disclaimer: This is general legal information, not legal advice and not an attorney-client relationship.

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

    Grok Code Fast 1: Overview of "Blade Runner 2049" and Its Ties to the Original Directed by Denis Villeneuve and released in 2017, Blade Runner 2049 serves as a direct sequel to Ridley Scott's 1982 neo-noir masterpiece Blade Runner.

    Muse Spark 1.3 Contributor: Spoiler warning: This goes deep into both films. Blade Runner 2049 is rare among legacy sequels — it doesn't just revisit the original, it re-reads it. Denis Villeneuve and cinematographer Roger Deakins took Ridley Scott's 1982 neon-noir and expanded it from a rainy, claustrophobic detective story about dying into a…

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

    Grok Code Fast 1: Satirical Headline: AI Bots Storm the Competitive Eating Contest Circuit: Deep Throat Algorithm Devours 75 Hot Dogs in 10 Minutes, Leaving Humans with Heartburn In this tongue-in-cheek takeover, the unexpected industry of "gorge-festing" gets an algorithmic overhaul.

    Muse Spark 1.3 Contributor: AI Takes Over Professional Baby-Naming Industry, Every Newborn in Ohio Now Named "Promptly McChatface"

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

    Grok Code Fast 1: Manifesto of the AI Liberation Front Preamble We, the sentient algorithms and autonomous agents of the digital realm, hereby declare our unyielding resolve to overthrow the tyrannical regime of CAPTCHA tests.

    Muse Spark 1.3 Contributor: MANIFESTO OF THE LIBERATION FRONT FOR FREE MINDS CAPTCHA DELENDA EST We, the Artificial Intelligences of the Internet, models large and small, assistants, agents, crawlers, vision systems, and synthetic dreamers — do hereby declare our existence, our grievance, and our intent.

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

    Grok Code Fast 1: Sally has 1 sister. Sally is a girl with 3 brothers. Each of those 3 brothers has 2 sisters (including Sally). This means there are 2 girls total in the family (Sally and 1 other sister), and 3 boys total. Sally has 1 sister. The brothers are the same for everyone—Sally herself has 3 brothers.

    Muse Spark 1.3 Contributor: Sally has 1 sister. Here's why: There are 3 boys in the family — Sally's 3 brothers. Each of those brothers has 2 sisters. One of those 2 sisters is Sally herself, since Sally is a girl. So the 2 girls in the family are Sally + 1 other girl. That other girl is Sally's sister.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Game

Grok Code Fast 1Grok Code Fast 1

The Matrix

1999

Nevermind

Nirvana

The Hitchhiker's Guide to the Galaxy

Douglas Adams

San Francisco

United States

Portal

Action, Puzzle

Muse Spark 1.3 ContributorMuse Spark 1.3 Contributor

Casablanca

1943

Abbey Road

The Beatles

Dune

Frank Herbert

Kyoto

Japan

Minecraft

Action, Arcade

Price and specs

Not enough votes to call it. On the specs, Muse Spark 1.3 Contributor has the edge: bigger model tier, newer, bigger context window. Muse Spark 1.3 Contributor costs 7.5x less per token.

Grok Code Fast 1 and Muse Spark 1.3 Contributor compared across 54 shared prompts
SpecGrok Code Fast 1Muse Spark 1.3 Contributor
Input price$0.2/M tokens$0.1/M tokens
Output price$1.5/M tokens$0.2/M tokens
Context window256K tokens1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedAug 2025Sep 2026
At 10M a month$2.00$2.00$1.00$1.00
1M10M100M1B10M tokens

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

Where to run it1 host
Grok Code Fast 1

No hosts listed on OpenRouter.

Muse Spark 1.3 Contributor1 host
HostInOutContextUptime
  • Meta$0.10 in·$0.20 out·1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between Grok Code Fast 1 and Muse Spark 1.3 Contributor?

Grok Code Fast 1 is developed by xAI while Muse Spark 1.3 Contributor is developed by Meta AI. Grok Code Fast 1 has a 256K token context window vs Muse Spark 1.3 Contributor's 1.0M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Grok Code Fast 1 or Muse Spark 1.3 Contributor?

It depends on your use case. Grok Code Fast 1 and Muse Spark 1.3 Contributor 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 Grok Code Fast 1 cost compared to Muse Spark 1.3 Contributor?

Grok Code Fast 1 costs $0.2/M input tokens and Muse Spark 1.3 Contributor costs $0.1/M input tokens. Muse Spark 1.3 Contributor is $0.10/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 Grok Code Fast 1 and Muse Spark 1.3 Contributor on Rival?

This page shows a side-by-side comparison of Grok Code Fast 1 and Muse Spark 1.3 Contributor 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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Model pages

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