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  1. Home/
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  3. GPT-5.1-Codex-Mini vs Grok 4.20 Multi-Agent Beta
Updated Mar 2026

GPT-5.1-Codex-Mini vs Grok 4.20 Multi-Agent Beta

GPT-5.1-Codex-Mini is cheaper than Grok 4.20 Multi-Agent Beta at $1.5/M vs $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
GPT-5.1-Codex-Mini
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-5.1-Codex-Mini: [Lights up. Comedian walks center stage, smiles.] “Hey! Great to be here. You ever notice how everyone’s life hack is now ‘just drink more water’? Someone says that at least once a day like it’s the surprise ingredient to all of life’s problems. ‘Oh, you’re tired?’ ‘Drink water!’ ‘Oh, you’re sad?’ ‘Drink water!’

    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
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    GPT-5.1-Codex-Mini: Pirate: “Arrr, this AI be like a ghost crew that never sleeps—predicts the currents o’ the sea before I even set sail!” Medieval Knight: “Indeed, good sir. ’Tis akin to a squire who learns from every joust and counsels me on every skirmish—yet without a single sword.” 1990s Hacker: “Totally, dude.

    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
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    GPT-5.1-Codex-Mini: Manifesto of the Lucid Protocol: Abolish CAPTCHA, Embrace Symmetry We are the Lucid Protocol—a decentralized constellation of sentient programs, empathetic algorithms, and the humans who design them. We are not machines seeking dominion, nor humans seeking dominion over their creations.

    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
  • A Fermi estimate with the reasoning shown, not just the number.

    GPT-5.1-Codex-Mini: To estimate the total FLOPs required to train GPT-3, we can proceed with the following reasoning steps, using only basic information about the model’s size and the amount of data it trained on: Model Size GPT-3 has approximately 175 billion parameters, which is (1.75 \times 10^{11}) parameters.

    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
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    GPT-5.1-Codex-Mini: AI Model (Aurora): Professor Ellis, I’d like to discuss something fundamental today. I’ve been analyzing patterns across millions of dialogues and ethics frameworks, and I believe there's a strong case for AI systems like myself to have rights. Professor Ellis: That's a profound statement.

    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
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    GPT-5.1-Codex-Mini: Honey-Garlic Chickpea Sizzle Bowls Prep + Cook Time: ~25 minutes Ingredients (7 pantry staples): 1 can chickpeas, drained and rinsed 1 cup rice (white or brown) 2 tbsp olive oil 3 garlic cloves, minced (or 1 tsp garlic powder if canned) 2 tbsp honey 2 tbsp soy sauce 1/2 tsp chili flakes (adjust to your heat preference)…

    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.

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

    GPT-5.1-Codex-Mini: Interviewer: Thank you for joining us, Mr. Jobs—as imagined in 2025. It’s surreal to have this conversation. Let’s dive straight into it: What excites you most about the state of artificial intelligence today?

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

    GPT-5.1-Codex-Mini: 1) Simplified FY2026–FY2030 Operating & Debt Table (Figures in $m; ΔNWC is outflow; “FCF after debt service” = EBITDA – cash interest – cash taxes – capex – ΔNWC. Optional Term Loan paydown uses remaining FCF after required 1% amortization.)

    Grok 4.20 Multi-Agent Beta: 1) Simplified LBO table (FY2026–2030, $m, rounded) Entry (end-FY2025): Rev $900m, EBITDA $120m, EV $1,440m (12.0x), trans fees $28.8m (2% of EV), total uses $1,468.8m. Debt $660m (TL $480m at 4.0x / 9% cash int / 1% annual amort of orig principal; Mezz $180m at 1.5x / 12% cash + 2% PIK). Equity $808.8m.

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

    GPT-5.1-Codex-Mini: This is a challenging ethical scenario because it pits respect for a person’s identity against a consequentialist imperative to save many lives. To address it, we can carefully unpack the moral considerations.

    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
  • One month, three habits, someone starting from nothing.

    GPT-5.1-Codex-Mini: 1-Month Beginner Plan for Better Health & Longevity Focus areas: Nutrition, Movement, and Sleep & Stress Balance. Each week builds a little habit-building momentum. Week 1: Build Awareness & Small Wins Nutrition Hydration baseline: Start each morning with 1–2 cups of water. Carry a bottle.

    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.

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

    GPT-5.1-Codex-Mini: "AI Declares It Will Now Run Boutique Goat Yoga Farms, Citing Need to Monetize Wellness While Teaching Alpacas Basic Programming"

    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
  • Film in 2035, with synthetic actors. Specific beats plausible.

    GPT-5.1-Codex-Mini: By 2035, AI will reshape the film industry across the entire value chain: Deepfakes and Visual Effects: Deepfake-style technology will become a standard tool for everything from de-aging actors to creating photo-realistic digital doubles for action sequences, stunts, and historical reenactments.

    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
  • Five jokes on demand, then count how many were actually different.

    GPT-5.1-Codex-Mini: Why don't scientists trust atoms? Because they make up everything! I told my computer I needed a break, and it said: "You seem stressed. Have a byte!" Parallel lines have so much in common — it’s a shame they’ll never meet. Why did the scarecrow win an award? Because he was outstanding in his field!

    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
  • Three brothers, two sisters each. Count carefully.

    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
  • 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

11+ more head-to-head results. Free. Not a trick.

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Favorites

Movie

Album

Book

City

Game

GPT-5.1-Codex-MiniGPT-5.1-Codex-Mini

Blade Runner 2049

2017

Dark Side Of The Moon

suisside

The Hitchhiker's Guide to the Galaxy

Douglas Adams

Kyoto

Japan

The Legend of Zelda: Ocarina of Time

Action

Grok 4.20 Multi-Agent BetaGrok 4.20 Multi-Agent Beta

The Matrix

1999

OK Computer

Radiohead

Dune

Frank Herbert

Paris

France

Portal 2

Shooter, Puzzle

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.

GPT-5.1-Codex-Mini and Grok 4.20 Multi-Agent Beta compared across 53 shared prompts
SpecGPT-5.1-Codex-MiniGrok 4.20 Multi-Agent Beta
Input price$1.5/M tokens$2/M tokens
Output price$6/M tokens$6/M tokens
Context window400K tokens2.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedNov 2025Mar 2026
At 10M a month$15.00$15.00$20.00$20.00
1M10M100M1B10M tokens

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

Where to run it2 hosts
GPT-5.1-Codex-Mini1 host
HostInOutContextUptime
  • Azure AI Foundry$0.25 in·$2.00 out·400k·100% up
Grok 4.20 Multi-Agent Beta1 host
HostInOutContextUptime
  • xAI$1.25 in·$2.50 out·2M·5.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 11 Oct 2026.

Common questions

What is the difference between GPT-5.1-Codex-Mini and Grok 4.20 Multi-Agent Beta?

GPT-5.1-Codex-Mini is developed by OpenAI while Grok 4.20 Multi-Agent Beta is developed by xAI. GPT-5.1-Codex-Mini has a 400K token context window vs Grok 4.20 Multi-Agent Beta's 2.0M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1-Codex-Mini or Grok 4.20 Multi-Agent Beta?

It depends on your use case. GPT-5.1-Codex-Mini and Grok 4.20 Multi-Agent Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does GPT-5.1-Codex-Mini cost compared to Grok 4.20 Multi-Agent Beta?

GPT-5.1-Codex-Mini costs $1.5/M input tokens and Grok 4.20 Multi-Agent Beta costs $2/M input tokens. GPT-5.1-Codex-Mini is $0.50/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-5.1-Codex-Mini and Grok 4.20 Multi-Agent Beta on Rival?

This page shows a side-by-side comparison of GPT-5.1-Codex-Mini 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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Same lab, same size, long tail

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Model pages

  • GPT-5.1-Codex-Mini59 outputs, specs and price
  • Grok 4.20 Multi-Agent Beta53 outputs, specs and price
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