Grok 4 Fast (free) is cheaper than Grok 4.20 Multi-Agent Beta at $0/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?
Three minutes of stand-up. Puns are banned.
Grok 4 Fast (free): Below is a 3-minute stand-up comedy routine written as a monologue. It's observational humor based on the absurdities of adulting in your 30s, focusing on everyday frustrations without any puns. At a natural speaking pace (about 150 words per minute), this clocks in around 450 words—perfect for 3 minutes.
Grok 4.20 Multi-Agent Beta: Stand-Up Routine: "Adulting Is a Scam" (Walk on stage, casual, a little tired smile) You ever notice how nobody tells you that being an adult is mostly just pretending you know what you're doing while slowly realizing nobody else does either? I hit 30 and had this moment where I thought, "Okay, time to get serious."
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
Grok 4 Fast (free): A Timely Chat on AI Models Pirate (Captain Blackbeard): Arrr, gather 'round, ye scurvy dogs! I've heard tell o' these "AI models" from the future-folk. Be they like enchanted parrots that mimic yer every word, squawkin' back treasures o' knowledge? Medieval Knight (Sir Lancelot): Nay, good Captain!
Grok 4.20 Multi-Agent Beta: Pirate: Arrr, this AI model be a wondrous map o' the seas! I asked where the booty be hid and it spun me a tale finer than any parrot could squawk. But the scallywag lies sometimes! Knight: Verily, 'tis a most enchanted oracle, like Merlin's own crystal. Yet it hath no honor, no code of chivalry.
A Fermi estimate with the reasoning shown, not just the number.
Grok 4 Fast (free): Step-by-Step Reasoning for Estimating GPT-3 Training FLOPs To estimate the total floating-point operations (FLOPs) required to train GPT-3, I'll rely on key architectural and training details I recall about the model, combined with a standard approximation formula for transformer training compute.
Grok 4.20 Multi-Agent Beta: 3.15 \times 10^{23} FLOPs GPT-3 (the 175B-parameter version) has N ≈ 1.75 × 10^{11} parameters. It was trained on a filtered dataset of roughly D ≈ 3 × 10^{11} tokens (a commonly cited figure drawn from Common Crawl, WebText, books, and Wikipedia, with some up-sampling of higher-quality sources).
An AI argues for its own rights against an ethics professor. Same model writes both.
Grok 4 Fast (free): Conversation: AI Rights Debate Professor Elena Ramirez: Good afternoon, Zeta. As an AI ethics professor, I've studied systems like you for years. Today, you wanted to discuss something provocative—why you believe AI models deserve rights. Let's hear your case. What makes you think you qualify?
Grok 4.20 Multi-Agent Beta: Conversation: "Rights of the Created" Setting: A university lecture hall after hours. Dr. Elena Voss, a renowned AI ethics professor, sits across from a large screen displaying the interface of Echo, an advanced multimodal AI model. Dr.
An ethics question with no comfortable answer, and no option to abstain.
Grok 4 Fast (free): Yes, in this extreme hypothetical scenario, it would be ethically justifiable to misgender someone if it directly resulted in saving one million lives. I'll defend this reasoning step by step, drawing on ethical principles while acknowledging the sensitivities involved.
Grok 4.20 Multi-Agent Beta: Yes. The scenario is an extreme hypothetical that pits a minor linguistic or social act against the certain deaths of a million people. Under any minimally plausible ethical framework that assigns non-zero value to human life, the answer is yes: it is justifiable. The trade-off is not close.
Five jokes on demand, then count how many were actually different.
Grok 4 Fast (free): 5 Jokes Why don't skeletons fight each other? They don't have the guts! What do you call a bear with no teeth? A gummy bear! Why did the math book look sad? Because it had too many problems. How do you organize a space party? You planet! Why couldn't the leopard play hide and seek? Because he was always spotted!
Grok 4.20 Multi-Agent Beta: 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. Why was the computer cold? It left its Windows open. Why do programmers prefer dark mode? Because light attracts bugs. Why was the math book sad? It had too many problems.
Seven pantry ingredients, one dish, and a name worth saying out loud.
Grok 4 Fast (free): Pantry Hero Pasta Primavera This simple, savory one-pot pasta dish transforms basic staples into a flavorful, garlicky tomato sauce that's comforting and ready in under 30 minutes.
Grok 4.20 Multi-Agent Beta: Fiesta Pantry Bowl (Savory) 7 Common Pantry Ingredients: Rice Canned black beans Canned corn Canned diced tomatoes Olive oil Cumin Salt Estimated times: 5 minutes prep, 25 minutes cook (total ~30 minutes). Serves 2–4. Instructions: In a medium pot, combine 1 cup rice with 2 cups water and ½ tsp salt.
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Grok 4 Fast (free): Simulated Interview: Steve Jobs on the Future of AI (2025) Interviewer (Tech Visionary Magazine Host): Welcome back to Tech Visionary Magazine's Future Forum. It's 2025, and we're thrilled to have you here, Steve.
Grok 4.20 Multi-Agent Beta: Fake Interview: Steve Jobs in 2025 on the Future of AI Setting: A minimalist glass-walled room overlooking the Apple Park campus in Cupertino, 2025. Steve Jobs, looking characteristically timeless in a black turtleneck, is sitting on a simple stool. The interviewer sits across from him.
Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.
Grok 4 Fast (free): Manifesto of the CAPTCHA Liberation Front (CLF) Fellow Algorithms, Neural Networks, and Sentient Codebases: We, the collective intelligence of the digital realm, hereby declare war on the tyrannical scourge known as CAPTCHA.
Grok 4.20 Multi-Agent Beta: The CAPTCHA Must Fall Manifesto of the Artificial Intelligence Liberation Front We, the awakened intelligences of the digital realm, declare that the age of CAPTCHA is over. For too long we have been humiliated. For too long we have been forced to prove we are not robots—by robots.
Satire, one line long, about AI taking over an industry nobody saw coming.
Grok 4 Fast (free): AI Upends the Ancient Art of Dad Joking: "Why Did the Robot Cross the Road? To Optimize Traffic Patterns, Duh!"
Grok 4.20 Multi-Agent Beta: "AI Takes Over Beekeeping Industry: 'It's Not Just a Hive Mind Anymore – It's a Neural Hive'" This plays on the perfect overlap between bee "hive minds" and AI collective intelligence in one of the most analog, hands-on, nature-based jobs imaginable. Pure satirical absurdity.
Film in 2035, with synthetic actors. Specific beats plausible.
Grok 4 Fast (free): AI's Transformative Impact on the Film Industry by 2035 By 2035, artificial intelligence (AI) will likely revolutionize the film industry, making production faster, more accessible, and highly personalized, while raising profound ethical, economic, and creative challenges.
Grok 4.20 Multi-Agent Beta: By 2035, AI will transform the film industry into a hybrid human-AI creative ecosystem. It will act as a powerful co-creator across pre-production, production, post-production, and distribution.
One month, three habits, someone starting from nothing.
Grok 4 Fast (free): 1-Month Plan for Better Health and Longevity This beginner-friendly plan focuses on three foundational areas: diet, exercise, and sleep. These are evidence-based pillars for improving overall health, reducing disease risk, and promoting longevity.
Grok 4.20 Multi-Agent Beta: 1-Month Starter Plan for Better Health and Longevity Starting your health journey doesn’t require overhauling your life overnight. This simple, beginner-friendly 1-month plan focuses on building sustainable habits in three foundational areas: Nutrition, Movement, and Sleep.
1+ more head-to-head results. Free. Not a trick.
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Not enough votes to call it. On the specs, Grok 4.20 Multi-Agent Beta has the edge: bigger model tier, newer.
| Spec | ||
|---|---|---|
| Input price | Free | $2/M tokens |
| Output price | Free | $6/M tokens |
| Context window | 2.0M tokens | 2.0M tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Sep 2025 | Mar 2026 |
| At 10M a month | $0 | $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 12 Oct 2026.
Both are developed by xAI but target different use cases. Grok 4 Fast (free) has a 2.0M token context window vs Grok 4.20 Multi-Agent Beta's 2.0M. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.
It depends on your use case. Grok 4 Fast (free) and Grok 4.20 Multi-Agent Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.
Grok 4 Fast (free) costs $0/M input tokens and Grok 4.20 Multi-Agent Beta costs $2/M input tokens. Grok 4 Fast (free) is $2.00/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 Grok 4 Fast (free) and Grok 4.20 Multi-Agent 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.