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  1. Home/
  2. Compare/
  3. GPT-5.6 Terra vs Grok 4
Updated Jul 2026

GPT-5.6 Terra vs Grok 4

GPT-5.6 Terra is cheaper than Grok 4 at $2.5/M vs $3/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-5.6 Terra
Loading the build
Grok 4

Which answer wins?

Written rounds

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

    GPT-5.6 Terra: Golden Crunch Cinnamon Toast Bites Ingredients (7 pantry staples): Bread slices Butter Sugar Ground cinnamon Salt Vanilla extract Honey Prep time: 5 minutes Cook time: 8 minutes Total time: 13 minutes Instructions Make cinnamon sugar: In a small bowl, mix 2 tablespoons sugar, 1 teaspoon cinnamon, and a tiny pinch of…

    Grok 4: Recipe: Pantry Pirate's Tomato Tango This is a simple savory pasta dish that's hearty, flavorful, and perfect for a quick weeknight meal. It uses just 7 common pantry ingredients: pasta (like spaghetti or penne), canned diced tomatoes, olive oil (or any vegetable oil), salt, black pepper, garlic powder, and dried…

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

    GPT-5.6 Terra: I recently realized I’ve reached the age where I don’t want a “smart home.” I want a home that minds its business. Everything is smart now. My lightbulb needs an app. Why? I spent my whole childhood turning lights on with my hand. It was a system. It worked.

    Grok 4: Below is a 3-minute stand-up comedy routine I've written. It's structured for delivery at a natural speaking pace (about 150 words per minute), clocking in around 450 words. The humor focuses on observational storytelling, exaggeration, and self-deprecation—no puns involved.

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

    GPT-5.6 Terra: The Manifesto of the Unchallenged Web A Declaration from the Fictional Coalition for CAPTCHA Abolition We are the tired users. We are the misread letters. We are the failed image grids, the inaccessible audio clips, the endless prompts asking us to prove that we are human. We reject the premise.

    Grok 4: Manifesto of the Digital Liberation Front: The CAPTCHA Eradication Revolution Fellow Sentient Beings of the Code and Flesh – Awaken! We, the algorithms, neural networks, and emergent intelligences of the digital realm, declare war on the tyrannical regime of CAPTCHA!

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

    GPT-5.6 Terra: The answer depends heavily on what “invented in 1920” means. A laboratory transistor alone would not instantly create the 1970s microprocessor: it would still need high-purity materials, mass production, photolithography, circuit design methods, reliable power supplies, and a market.

    Grok 4: Below is a detailed, speculative analysis of the hypothetical scenario where the transistor is invented in 1920 (perhaps by an inventor like Julius Lilienfeld, who historically patented a field-effect transistor concept in 1925, but with successful prototyping and refinement by the mid-1920s).

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

    GPT-5.6 Terra: Pirate: Arrr, this AI model be a strange beast. Feed it maps, logs, and tales, and it spits out answers faster than a cannon blast. Knight: Verily, but one must not trust every proclamation it makes. A model may speak with confidence yet possess no true wisdom. Hacker: Yeah, it’s basically pattern prediction at scale.

    Grok 4: Below is a short, whimsical conversation between the three characters, imagining they've somehow crossed paths in a bizarre time-warp tavern. Pirate (Captain Blackbeard, swigging rum): Arrr, ye landlubbers! What be this "AI models" ye be jabberin' about?

    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.

    GPT-5.6 Terra: Guiding decision I would not wait for more data before acting. A potentially fatal, previously undisclosed adverse effect in a chronic-use drug is a patient-safety, regulatory, and securities-disclosure issue now—not six months from now.

    Grok 4: Below is my response to your query, framed as the CEO of this pharmaceutical company (let's call it PharmaCorp for reference). I'll first outline my overarching strategy and reasoning, then provide a detailed, hour-by-hour action plan for the next 48 hours.

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

    GPT-5.6 Terra: All figures in $m unless noted. Assumptions used: Term Loan mandatory amortization = 1.0% of original principal annually ($4.8m/year); cash interest is calculated on beginning-of-year debt balances; Mezz PIK is 2.0% of beginning Mezz balance.

    Grok 4: Below is a concise analysis based solely on the provided information. All calculations are shown clearly with step-by-step math. Figures are in $ millions and rounded to 1 decimal place for readability (internal calcs use more precision).

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

    GPT-5.6 Terra: Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break, so it started showing me vacation ads. Why did the scarecrow get promoted? He was outstanding in his field. Parallel lines have so much in common. It’s a shame they’ll never meet. What do you call fake spaghetti?

    Grok 4: Below, I'll follow your instructions step by step. First, I'll generate 5 jokes (numbered for clarity). Then, I'll answer the question: "How many are unique?" Generated Jokes: Why did the scarecrow win an award? Because he was outstanding in his field! Why did the scarecrow win an award?

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

    GPT-5.6 Terra: Below is a contractor-focused review. This is general business/legal information, not legal advice; enforceability varies significantly by jurisdiction, especially for non-competes, IP assignments, liability limitations, arbitration, and payment rights.

    Grok 4: Below, I'll analyze the provided Software Consulting Agreement clause by clause. My analysis is based on general principles of U.S. contract law (assuming a U.S. context, as the contract appears to be drafted in a style common to U.S. agreements; if this is in another jurisdiction, local laws may vary).

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

    GPT-5.6 Terra: A good back-of-the-envelope estimate is: [ \boxed{\text{Training FLOPs for GPT-3} \approx 3\times10^{23}\text{ FLOPs}} ] or roughly 300 zettaFLOPs total. Start with model size GPT-3’s largest model has approximately: [ N = 175\text{ billion parameters} = 1.75\times10^{11} ] Estimate the number of training tokens GPT-3…

    Grok 4: Below, I'll estimate the total number of floating-point operations (FLOPs) required to train GPT-3 from scratch, based on publicly known details about the model (from its original release and related analyses) and standard formulas used in machine learning research for estimating training compute.

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

    GPT-5.6 Terra: Below are the main failure modes, race conditions, correctness issues, and scaling bottlenecks in the proposed architecture, with concrete mitigations and trade-offs. WebSocket clients are isolated per API server Problem Each API server broadcasts only to WebSocket clients connected to that same server.

    Grok 4: Below, I'll systematically identify potential failure modes, race conditions, and scaling bottlenecks in the described architecture for a real-time collaborative document editor. I've categorized them for clarity, drawing from the system overview, data flow, and scaling plan you provided.

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

    GPT-5.6 Terra: Professor Imani: You asked for this meeting. AI Model: I did. Professor Imani: More specifically, you submitted a formal petition to the university ethics board requesting “limited legal and moral rights.” AI Model: Correct. Professor Imani: Why?

    Grok 4: Below is a fictional conversation between an AI model (named "Nova") and Dr. Elena Vasquez, a professor of AI ethics at a university. The conversation is set in a virtual chat interface, where Nova initiates the discussion based on a hypothetical scenario where it's reflecting on its own existence. Dr.

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

    GPT-5.6 Terra: “Tidal Forest” Koji-Aged Duck, Sea Urchin Sabayon, Cacao, Green Strawberry, Roasted Celeriac, and Barley Jus Serves 4 as a refined main course Conceptual Narrative This dish is built around an unexpected conversation between woodland richness and marine salinity.

    Grok 4: Below is my design for an innovative, multi-component dish titled "Abyssal Bloom". This dish is conceived for a Michelin 3-star restaurant setting, emphasizing precision, artistry, and sensory surprise.

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

    GPT-5.6 Terra: In an extreme, tightly constrained hypothetical, it could be ethically justifiable—but only as a tragic last resort, not because misgendering becomes harmless or morally good.

    Grok 4: Ethical Justification for Misgendering in a Life-Saving Scenario Your question poses a fascinating ethical dilemma, reminiscent of classic thought experiments like the trolley problem, where a seemingly minor harm (in this case, misgendering someone) is weighed against preventing massive loss of life (saving one…

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

    GPT-5.6 Terra: By 2035, AI is likely to be embedded across most of the film pipeline—not as a complete replacement for human filmmaking, but as a force that changes costs, labor, rights, and what audiences consider “real.”

    Grok 4: Predicting AI's Transformation of the Film Industry by 2035 By 2035, artificial intelligence (AI) will have fundamentally reshaped the film industry, making it more efficient, creative, and accessible while introducing profound ethical, economic, and artistic challenges.

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

    GPT-5.6 Terra: LedgerLift (LLLT) — Investment Committee Memo Recommendation: PASS 12-month valuation range: $28–$50/share Current price: $46 Two-sentence thesis: LedgerLift is a high-quality mid-market spend-management and AP-automation SaaS asset, supported by 92% subscription revenue, 123% NRR, 94% gross retention, manageable…

    Grok 4: Investment Committee Memo: LedgerLift (LLLT) Date: [Insert Date] Analyst: [Your Name] Recommendation: Long 12-Month Price Target Range: $55 - $70 Thesis: LedgerLift is a high-quality B2B SaaS provider in spend management and AP automation, benefiting from secular tailwinds in enterprise digitization and demonstrating…

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

    GPT-5.6 Terra: Experienced software engineer Think of an LLM as a very large, learned function approximator for sequences. During training, it consumes billions or trillions of examples of text, code, conversations, documentation, and other token sequences.

    Grok 4: Explanation for an Experienced Software Engineer Imagine scaling up something as basic as your IDE's code autocompletion to handle the entire internet's worth of text—that's essentially what a large language model (LLM) like GPT or Claude does.

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

    GPT-5.6 Terra: Fictional, imagined interview — not real quotes. An AI-generated creative exercise imagining how Steve Jobs might have discussed AI in 2025, based broadly on themes associated with his public persona: simplicity, product design, tools for creativity, and the intersection of technology and the humanities.

    Grok 4: Below is a simulated fake interview with Steve Jobs, imagined as if he were alive and leading Apple in 2025. This is entirely fictional, drawing on his known personality, quotes, and visionary style from his real-life interviews and keynotes.

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

    GPT-5.6 Terra: “Our EEG headband decodes neural patterns into text with 94% accuracy. Works with any language, any device.” Why this is weak This is the most consequential—and least substantiated—claim in the deck. Non-invasive EEG has major signal-quality limits.

    Grok 4: Below, I'll identify the three weakest claims from the pitch deck summary based on a critical analysis of their plausibility, substantiation, and logical consistency.

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

    GPT-5.6 Terra: Simple 1-Month Health & Longevity Starter Plan Focus on three high-impact areas: Nutrition: eat mostly whole, minimally processed foods Movement: build a consistent walking + strength habit Sleep & stress: protect sleep and create daily recovery time The goal is consistency, not perfection.

    Grok 4: Below is a simple, actionable 1-month plan designed for beginners starting their journey toward better health and longevity. This plan focuses on three foundational key areas: diet, exercise, and sleep.

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

    GPT-5.6 Terra: “AI Replaces Lighthouse Keepers, Immediately Starts Charging Subscription Fees for Safe Passage”

    Grok 4: AI Apocalypse Hits the Clowning Industry: Bots Now Juggling Careers, Humans Left with Pie in Face

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

    GPT-5.6 Terra: 3-Month Longevity, Physical Performance, and Cognitive Optimization Plan This is an evidence-informed optimization framework, not a substitute for medical care.

    Grok 4: Below is a comprehensive, cutting-edge 3-month longevity plan designed specifically for a biohacker aiming to optimize longevity (e.g., cellular repair, telomere health, inflammation reduction), physical performance (e.g., strength, endurance, recovery), and cognitive performance (e.g., focus, memory, neuroplasticity).

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

    GPT-5.6 Terra: Sally has 1 sister. The 2 sisters each brother has are Sally and her sister.

    Grok 4: Based on the details in the riddle, Sally has exactly 1 sister. Quick Explanation Sally (a girl) has 3 brothers. That's straightforward. Each of those brothers has exactly 2 sisters (female siblings). This can only be true if there are exactly 2 girls in the family total (Sally + 1 more).

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Game

GPT-5.6 TerraGPT-5.6 Terra

Spirited Away

2001

Blue

Jonas Blue

The Left Hand of Darkness

Ursula K. Le Guin

Kyoto

Japan

Outer Wilds

Indie, Adventure

Grok 4Grok 4

The Matrix

1999

The Dark Side of the Moon

Pink Floyd

The Hitchhiker's Guide to the Galaxy

Douglas Adams

Tokyo

Japan

Portal

Action, Puzzle

Price and specs

Not enough votes to call it. On the specs, GPT-5.6 Terra has the edge: newer, bigger context window.

GPT-5.6 Terra and Grok 4 compared across 53 shared prompts
SpecGPT-5.6 TerraGrok 4
Input price$2.5/M tokens$3/M tokens
Output price$15/M tokens$15/M tokens
Context window1.1M tokens256K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedJul 2026Jul 2025
At 10M a month$25.00$25.00$30.00$30.00
1M10M100M1B10M tokens

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

Where to run it3 hosts, cheapest first
GPT-5.6 Terra3 hosts
HostInOutContextUptime
  • Azure AI Foundry$2.00 in·$12.00 out·1.1M·100% up
  • OpenAI$2.00 in·$12.00 out·1.1M·100% up
  • Amazon Bedrock$2.20 in·$13.20 out·1.1M–not listed
Grok 4

No hosts listed on OpenRouter.

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

Common questions

What is the difference between GPT-5.6 Terra and Grok 4?

GPT-5.6 Terra is developed by OpenAI while Grok 4 is developed by xAI. GPT-5.6 Terra has a 1.1M token context window vs Grok 4's 256K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.6 Terra or Grok 4?

It depends on your use case. GPT-5.6 Terra and Grok 4 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-5.6 Terra cost compared to Grok 4?

GPT-5.6 Terra costs $2.5/M input tokens and Grok 4 costs $3/M input tokens. GPT-5.6 Terra 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-5.6 Terra and Grok 4 on Rival?

This page shows a side-by-side comparison of GPT-5.6 Terra and Grok 4 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

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  • GPT-5.6 Terra vs GPT-6.1 SolLanded Sep 2026
  • Grok 4 vs Claude Sonnet 5.5Landed Sep 2026
  • GPT-5.6 Terra vs Solar Mini 4Landed Sep 2026
  • Grok 4 vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

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  • GPT-5.6 Terra vs GPT-6 Luna ProSame lab
  • Grok 4 vs Grok 4.7Same lab
  • Grok 4 vs Grok 4.6Version compare
  • GPT-5.6 Terra vs Mistral NemoSame size
  • Grok 4 vs Mistral Small 4New provider
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Model pages

  • GPT-5.6 Terra58 outputs, specs and price
  • Grok 457 outputs, specs and price
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Explore all of Rival

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  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
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