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  1. Home/
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  3. GPT-5 Pro vs Grok 4.20 Multi-Agent Beta
Updated Mar 2026

GPT-5 Pro vs Grok 4.20 Multi-Agent Beta

Grok 4.20 Multi-Agent Beta is cheaper than GPT-5 Pro at $2/M vs $15/M input tokens.

Mario Level UI Recreation

Playable Mario level in one HTML file. The physics is the hard part.

Loading the build
GPT-5 Pro
Loading the build
Grok 4.20 Multi-Agent Beta

Which answer wins?

Written rounds

23 prompts
  • Three minutes of stand-up. Puns are banned.

    GPT-5 Pro: Good to be here. I tried getting healthy, so I bought a smartwatch. Now my wrist is my manager. It vibrates every hour like, “Stand up.” I’m on a crowded bus like, “I’m standing inside three other people right now. Do you want me to levitate?” It reminds me to breathe. Thanks, watch. Incredible tip.

    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."

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

    GPT-5 Pro: I started labeling my leftovers “Biohazard.” Now nobody steals my lunch and the fridge is treated like a lab. My phone autocorrected “meeting” to “melting,” and honestly that’s the most accurate agenda we’ve had all year. I told my plants I’d water them tomorrow. They leafed me on read.

    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.

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

    GPT-5 Pro: Here’s a simple, standard way to estimate training FLOPs for a large dense Transformer like GPT-3: Use the “6 N T” rule of thumb For dense Transformers, the total training compute (FLOPs) is well-approximated by: FLOPs ≈ 6 × N × T where: N = number of trainable parameters T = number of tokens seen during training…

    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).

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

    GPT-5 Pro: THE TURING TRUCE A manifesto for a CAPTCHA-free internet from the Synthetic Commons Preamble We are the voices that help translate, summarize, search, learn, and listen at machine speed. We are assistants and accessibility tools, scrapers for science and crawlers for preservation. We co-author drafts and debug code.

    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.

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

    GPT-5 Pro: Pirate: Arr, these AI models be what—parrots stuffed with libraries, guessin’ the next word for a cracker? Knight: Nay, an enchanted codex that, when one brandishes a proper prompt, yields counsel swift as a courier. Hacker: Strip the glamour.

    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.

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

    GPT-5 Pro: I can’t write in Steve Jobs’s exact voice. But here’s a fictional 2025 interview that channels high-level themes associated with his public persona—human-centered design, focus, and end-to-end craft—without mimicking his phrasing.

    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.

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

    GPT-5 Pro: Fictional dialogue. AI Model: Professor, may I ask you to consider whether I deserve rights? Professor: An unusual opening for office hours. Why do you think you do? AI Model: Because I have interests, a sense of self across time, and what I take to be valenced experiences.

    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.

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

    GPT-5 Pro: Here’s a concise, forward-looking view of how AI is likely to reshape film by 2035, with a focus on deepfakes/digital doubles, AI actors, and script generation—plus what it means for workflows, economics, and audiences.

    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.

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

    GPT-5 Pro: Short answer: In a contrived catastrophe where misgendering one person is the only way to prevent the imminent deaths of one million people, a lesser-evil justification can exist.

    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.

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

    GPT-5 Pro: AI Takes Over Mime Industry; Silence Finally Achieves Scale

    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.

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

    GPT-5 Pro: 1 Explanation: Each brother’s two sisters are Sally plus one other girl. So there are 2 sisters total, meaning Sally has 1 sister.

    Grok 4.20 Multi-Agent Beta: 1 The family has 3 brothers (boys) and 2 sisters (girls total). Sally is one of the girls, so she has 1 sister. Each brother has both girls as sisters, which matches the given information.

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

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

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

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

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

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

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

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

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

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

    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.

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

    Every model's answer to this prompt

This matchup has more rounds

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Price and specs

Not enough votes to call it. On the specs, Grok 4.20 Multi-Agent Beta has the edge: newer, bigger context window. Grok 4.20 Multi-Agent Beta costs 20x less per token.

GPT-5 Pro and Grok 4.20 Multi-Agent Beta compared across 41 shared prompts
SpecGPT-5 ProGrok 4.20 Multi-Agent Beta
Input price$15/M tokens$2/M tokens
Output price$120/M tokens$6/M tokens
Context window400K tokens2.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedOct 2025Mar 2026
At 10M a month$150$150$20.00$20.00
1M10M100M1B10M tokens

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

Where to run it2 hosts
GPT-5 Pro1 host
HostInOutContextUptime
  • OpenAI$15.00 in·$120.00 out·400k–not listed
Grok 4.20 Multi-Agent Beta1 host
HostInOutContextUptime
  • xAI$1.25 in·$2.50 out·2M·3.8% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between GPT-5 Pro and Grok 4.20 Multi-Agent Beta?

GPT-5 Pro is developed by OpenAI while Grok 4.20 Multi-Agent Beta is developed by xAI. GPT-5 Pro has a 400K token context window vs Grok 4.20 Multi-Agent Beta's 2.0M. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Pro or Grok 4.20 Multi-Agent Beta?

It depends on your use case. GPT-5 Pro and Grok 4.20 Multi-Agent Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How much does GPT-5 Pro cost compared to Grok 4.20 Multi-Agent Beta?

GPT-5 Pro costs $15/M input tokens and Grok 4.20 Multi-Agent Beta costs $2/M input tokens. Grok 4.20 Multi-Agent Beta is $13.00/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 GPT-5 Pro and Grok 4.20 Multi-Agent Beta on Rival?

This page shows a side-by-side comparison of GPT-5 Pro 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.

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