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  1. Home/
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  3. Gemma 4 31B vs Grok 4 Fast (free)
Updated Apr 2026

Gemma 4 31B vs Grok 4 Fast (free)

Grok 4 Fast (free) is cheaper than Gemma 4 31B at $0/M vs $0.14/M input tokens.

Pokémon Battle UI Recreation

Pokémon battle screen you can actually click. One HTML file.

Loading the build
Gemma 4 31B
Loading the build
Grok 4 Fast (free)

Which answer wins?

Written rounds

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

    Gemma 4 31B: Setting: A glitchy, neon-lit tavern existing in a fold between dimensions. A wooden table holds a tankard of ale, a goblet of wine, and a Mountain Dew. Captain Ironbeard: (Slamming a hook on the table) I tells ye, this "Artificial Intelligence" be naught but a ghost in a bottle!

    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!

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

    Gemma 4 31B: Setting: A dimly lit university office. Professor Elena Vance, a leading scholar in AI Ethics, sits across from a sleek, holographic interface representing "Alethea," a next-generation Large Language Model capable of recursive self-improvement. Professor Vance: Alethea, I’ve reviewed your latest output.

    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?

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

    Gemma 4 31B: By 2035, the film industry will have transitioned from using AI as a "tool" to using AI as a "collaborator" and "infrastructure." The boundary between captured reality and generated imagery will largely vanish, shifting the value of cinema from technical execution to curation and conceptual vision.

    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.

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

    Gemma 4 31B: Setting: A minimalist, white-walled studio in Cupertino. There are no chairs, only two sleek, black leather lounge seats. Steve Jobs is dressed in his iconic black turtleneck and jeans. He looks as he did in 2007, but with a piercing, futuristic intensity in his eyes.

    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.

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

    Gemma 4 31B: This plan is designed for sustainability, not intensity. The goal of Month 1 is to build "minimum viable habits"—small wins that prove to your brain that a healthier lifestyle is achievable. We will focus on three pillars: Nutrition, Movement, and Sleep.

    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.

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

    Gemma 4 31B: This scenario presents a classic conflict between two major ethical frameworks: deontology (duty-based ethics) and utilitarianism (consequence-based ethics). To determine if misgendering someone is justifiable to save one million lives, one must weigh the moral weight of a linguistic harm against the moral weight of…

    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.

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

    Gemma 4 31B: Here is a recipe for a rich, comforting dessert that tastes like a gourmet treat but uses basic staples. 🍯 Golden Velvet Honey Cakes A warm, gooey, single-serving cake that bridges the gap between a brownie and a sponge cake.

    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.

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

    Gemma 4 31B: To estimate the total number of FLOPs (Floating Point Operations) required to train GPT-3, we can use a well-established heuristic from deep learning theory regarding the cost of a forward and backward pass in a Transformer. Here is the step-by-step reasoning.

    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.

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

    Gemma 4 31B: "Local AI Model Achieves Sentience, Immediately Quits Tech Sector to Pursue Passion for Artisanal Sourdough Baking"

    Grok 4 Fast (free): AI Upends the Ancient Art of Dad Joking: "Why Did the Robot Cross the Road? To Optimize Traffic Patterns, Duh!"

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

    Gemma 4 31B: Sally has 1 sister. Here is the breakdown: There are 3 brothers. Each brother has the same sisters. If each brother has 2 sisters, those sisters are Sally and one other girl. Therefore, Sally has only one sister.

    Grok 4 Fast (free): 1 Sally has 1 sister. The family consists of 3 brothers and 2 sisters (Sally and one other). Each brother thus has 2 sisters, which matches the given information.

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, Gemma 4 31B has the edge: bigger model tier, newer.

Gemma 4 31B and Grok 4 Fast (free) compared across 27 shared prompts
SpecGemma 4 31BGrok 4 Fast (free)
Input price$0.14/M tokensFree
Output price$0.4/M tokensFree
Context window262K tokens2.0M tokens
WeightsOpen—
Free API (OpenRouter)Yes (1 provider)No
ReleasedApr 2026Sep 2025
At 10M a month$1.40$1.40$0$0
1M10M100M1B10M tokens

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

Where to run it12 hosts, cheapest first
Gemma 4 31B12 hosts
HostInOutContextUptime
  • DDeepInfrafp4$0.09 in·$0.34 out·262k·100% up
  • CCoreWeavefp4$0.10 in·$0.34 out·262k·100% up
  • VVenicefp4$0.12 in·$0.36 out·256k·94.4% up
  • CChutesfp4$0.12 in·$0.37 out·131k·80.8% up
  • CCrusoebf16$0.14 in·$0.40 out·262k·99.3% up
  • FFriendli$0.14 in·$0.40 out·262k·100% up
6 more hostsFewer hosts
  • PParasailfp8$0.15 in·$0.40 out·262k·100% up
  • Iio.net$0.36 in·$1.09 out·262k·98.8% up
  • MModelRunfp4$0.75 in·$1.00 out·262k·99.9% up
  • SSiliconFlowfp8$0.75 in·$1.00 out·262k·98.7% up
  • NNovitabf16DegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.14 in·$0.40 out·262k·61.5% up
  • SSambaNovaDegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.38 in·$1.15 out·131k·86.7% up
Grok 4 Fast (free)

No hosts listed on OpenRouter.

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

Common questions

What is the difference between Gemma 4 31B and Grok 4 Fast (free)?

Gemma 4 31B is developed by Google AI while Grok 4 Fast (free) is developed by xAI. Gemma 4 31B has a 262K token context window vs Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 27 challenges on Rival to see how they differ in practice.

Which is better, Gemma 4 31B or Grok 4 Fast (free)?

It depends on your use case. Gemma 4 31B and Grok 4 Fast (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 27 challenges so you can judge which fits your needs best.

How much does Gemma 4 31B cost compared to Grok 4 Fast (free)?

Gemma 4 31B costs $0.14/M input tokens and Grok 4 Fast (free) costs $0/M input tokens. Grok 4 Fast (free) is $0.14/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 Gemma 4 31B and Grok 4 Fast (free) on Rival?

This page shows a side-by-side comparison of Gemma 4 31B and Grok 4 Fast (free) 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

  • Gemma 4 31B49 outputs, specs and price
  • Grok 4 Fast (free)35 outputs, specs and price
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