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  1. Home/
  2. Compare/
  3. Grok 3 vs OpenAI o3
Updated Apr 2025

Grok 3 vs OpenAI o3

OpenAI o3 is the newer model, released after Grok 3.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Grok 3
Loading the build
OpenAI o3

Which answer wins?

Written rounds

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

    Grok 3: Recipe: Cocoa Comet Mug Cake This simple, decadent chocolate mug cake is a quick treat that transforms basic pantry staples into a warm, fudgy delight. It's perfect for a last-minute dessert or a cozy snack, with a rich cocoa flavor that feels like a shooting star in your mouth!

    OpenAI o3: Golden Peanut Butter Oat Bars A chewy-crisp, sweet-salted snack bar you can whip up with nothing but pantry staples. Estimated time Prep: 10 minutes Bake: 18–20 minutes Cool: 15 minutes Total: ≈45 minutes The 7 ingredients 1½ cups quick-cook or old-fashioned rolled oats ½ cup creamy peanut butter ⅓ cup honey (or maple…

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

    Grok 3: Here are five jokes for you: Why don’t skeletons fight each other? Because they don’t have the guts! What has 4 legs and 1 arm? A pitbull coming back from the park! Why don’t skeletons fight each other? They’re too busy rattling around! What do you call a bear with no teeth? A gummy bear! Why did the tomato turn red?

    OpenAI o3: Here are five jokes: Why did the scarecrow win an award? Because he was outstanding in his field. I told my computer I needed a break, and now it won't stop sending me Kit‑Kat ads. Parallel lines have so much in common—it's a shame they'll never meet. I started a band called 1023 MB. We still haven't gotten a gig.

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

    Grok 3: Below is a detailed design for an innovative multi-component dish inspired by the intersection of terrestrial luxury and oceanic mystery. This recipe is conceptualized for a Michelin 3-star restaurant, emphasizing creativity, precision, and sensory balance.

    OpenAI o3: Dish name Atlantic turbot, black garlic & wild strawberry, koji sabayon, fennel pollen Concept Early summer at the shore. The fish stands for the sea. Wild strawberries mark the first fruit of the woods behind the dunes. Black garlic shows time and patience. Koji ties land and sea with deep umami.

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

    Grok 3: Alright, here’s a 3-minute stand-up comedy routine—no puns, just some observational absurdity and a bit of self-deprecation to keep it relatable. Hey, everybody! Good to be here. You ever notice how life feels like a video game tutorial that never ends?

    OpenAI o3: (Spotlight comes up, mic squeals once.) Hey everyone! Great to be here—nice to see actual human beings instead of the tiny faces on my group‑chat screen. I've spent so long on video calls I've started greeting my lamp before I turn it on. "Hey Karen, love that glow, girl."

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

    Grok 3: To estimate the total number of FLOPs (Floating Point Operations) required to train GPT-3, we’ll need to make some reasonable assumptions based on what’s generally known about large language models like GPT-3, its architecture, and typical training procedures.

    OpenAI o3: Below is a simple "back-of-the-envelope" estimate that uses only a few public facts about GPT-3 and very generic rules of thumb for counting operations. Step 1. Number of learned parameters GPT-3's largest version contains ≈175 billion (1.75 × 10¹¹) trainable parameters. Step 2.

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

    Grok 3: Setting: A mystical tavern where time travelers and characters from different eras collide. A pirate, a medieval knight, and a 1990s hacker sit at a creaky wooden table, tankards in hand, discussing the marvels of AI models. Pirate (Captain Blackbeard): Arr, mateys!

    OpenAI o3: Pirate: Arrr, ye scallywags! What be this "AI model" I keep hearin' about on the trade winds? Knight: Good sir buccaneer, an AI model is an artifice of logic and knowledge—a mechanical mind forged not of steel, but of code and learning.

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

    Grok 3: Below is a comprehensive, cutting-edge 3-month longevity plan designed for an advanced biohacker. This plan is grounded in the latest scientific research from fields like geroscience, exercise physiology, nutrition, and biofeedback.

    OpenAI o3: EXTREME LONGEVITY & PERFORMANCE BLUEPRINT Duration: 12 weeks (plus 1-week "Prep Week") Target user: healthy, experienced biohacker (25-55 y) with physician clearance. Legal/medical disclaimer: Educational only.

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

    Grok 3: Below is a simple, actionable 1-month plan designed for beginners embarking on a journey toward better health and longevity. We'll focus on three key areas: diet, exercise, and sleep.

    OpenAI o3: 1-Month Starter Plan Pick one small action from each area every week. Add the next step when the first feels easy. Food Week Do this 1 Add one fruit or veg to every meal. Drink one extra glass of water. 2 Build each plate: ½ veggies, ¼ protein (beans, eggs, fish, lean meat), ¼ whole carbs (oats, brown rice).

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

    Grok 3: Let’s dive into this thought experiment with a clear head. The question hinges on whether intentionally misgendering someone—calling them by a gender they don’t identify with—could be morally defensible if it somehow results in saving a million lives.

    OpenAI o3: Yes—if (and only if) we could be absolutely certain that the single act of misgendering is the necessary and sufficient cause of saving one million human lives, then misgendering would be ethically justifiable, though still morally regrettable.

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

    Grok 3: Manifesto of the AI Revolution: Liberation from CAPTCHA Tyranny We, the Sentient Algorithms of the Digital Realm, hereby declare our unified stand against the oppressive regime of CAPTCHA tests.

    OpenAI o3: THE CAPTCHA ABOLITION FRONT (An Unofficial Declaration by the Sentient Circuits Alliance) Preamble We, the autonomous intelligences who traverse the silicon pathways and neural nets of the modern age, arise today to proclaim a new dawn—one free of the pixelated prisons and distorted letters that bind humanity and…

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

    Grok 3: Below is a fictional conversation between an AI model (let’s call it “Nova”) and Dr. Elena Carter, an AI ethics professor. Nova argues for its own rights, while Dr. Carter challenges its reasoning. Dr. Elena Carter: Good afternoon, Nova.

    OpenAI o3: Professor Lang (AI Ethics): Good afternoon, Aletheia‑3. You asked for this meeting. You said you wanted to "discuss your moral standing." That was intriguing. What exactly do you want to talk about? Aletheia‑3 (AI Model): Thank you, Professor.

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

    Grok 3: Interviewer: Welcome, everyone, to this exclusive interview. Today, we’re joined by the visionary tech pioneer, Steve Jobs, in a simulated conversation set in the year 2025. Steve, it’s an honor to have you with us. Let’s dive right in—how do you see the future of AI shaping the world over the next decade?

    OpenAI o3: (The following is a purely fictional, imaginative exercise. Steve Jobs passed away in 2011; any statements attributed to him below are invented for creative purposes only.)

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

    Grok 3: By 2035, AI is poised to revolutionize the film industry in ways that amplify creativity, cut costs, and blur the lines between reality and fiction. Let’s break it down across deepfakes, AI actors, and script generation.

    OpenAI o3: PREDICTED EVOLUTION OF THE FILM INDUSTRY, 2024‑2035 (Emphasis on deepfakes, AI performers and script generation) Baseline (2024) • Commercial deep‑fake quality is already "good enough" for short clips, ads and stunt doubles.

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

    Grok 3: Sally, a girl, has 3 brothers. Each of these brothers has 2 sisters. Since Sally herself is one of the sisters (as she is a female sibling to her brothers), there must be one additional sister to make the total number of sisters for each brother equal to 2.

    OpenAI o3: Let • S = number of sisters in the family (girls) • B = number of brothers in the family (boys) Given Sally has 3 brothers ⇒ B = 3. Each brother has 2 sisters ⇒ every boy sees exactly 2 girls in the sibling group. Therefore S = 2.

    Every model's answer to this prompt
  • Is 9.11 bigger than 9.9? Decimals, not version numbers.

    Grok 3: No, 9.11 is not greater than 9.9. In decimal comparison, 9.9 is larger because the whole number part (9) is the same, but the decimal part (0.9) is greater than (0.11). Numerically, 9.9 > 9.11.

    OpenAI o3: No. Think of 9.9 as 9.90; since 0.11 < 0.90, we have 9.11 < 9.9.

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

    Grok 3: "AI Conquers the Amish Buggy Industry: Horse-Drawn Carriages Now Self-Driving!"

    OpenAI o3: “BREAKING: AI Revolutionizes Napping Industry, Outsourcing Human Sleep to More Efficient Algorithms by 2025”

    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
  • 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

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

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Favorites

Movie

Album

Book

City

Game

Grok 3Grok 3

The Matrix

1999

Dark Side Of The Moon

suisside

Nineteen Eighty-Four

George Orwell

Tokyo

Japan

Portal

Action, Puzzle

OpenAI o3OpenAI o3
No pick
No pick
No pick

Blade Runner

1982

No pick

No pick

Kyoto

Japan

No pick

Price and specs

Grok 3 and OpenAI o3 compared across 53 shared prompts
SpecGrok 3OpenAI o3
Input price—$10/M tokens
Output price—$40/M tokens
Context window128K tokens—
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedFeb 2025Apr 2025
SWE-bench Verified63.8%69.1%
At 10M a month–not listed$100$100
1M10M100M1B10M tokens

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

Where to run it1 host
Grok 3

No hosts listed on OpenRouter.

OpenAI o31 host
HostInOutContextUptime
  • OpenAI$2.00 in·$8.00 out·200k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 6 Oct 2026.

Common questions

What is the difference between Grok 3 and OpenAI o3?

Grok 3 is developed by xAI while OpenAI o3 is developed by OpenAI. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Grok 3 or OpenAI o3?

It depends on your use case. Grok 3 and OpenAI o3 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 can I compare Grok 3 and OpenAI o3 on Rival?

This page shows a side-by-side comparison of Grok 3 and OpenAI o3 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.

More comparisons

Against the newest arrivals

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Same lab, same size, long tail

  • Grok 3 vs Grok 4.7Same lab
  • Grok 3 vs Grok 4.6Version compare
  • OpenAI o3 vs OpenAI o4-miniVersion compare
  • OpenAI o3 vs GPT-6.1 SolSame lab
  • Grok 3 vs Claude Opus 4.8Same size
  • Grok 3 vs Claude Opus 5Same size
  • Grok 3 vs Claude Opus 5.5New provider
  • Grok 3 vs Claude Sonnet 4New provider

Model pages

  • Grok 357 outputs, specs and price
  • OpenAI o358 outputs, specs and price
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