Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. Gemini 3.1 Pro PreviewvsGrok 3 Thinking
Updated Feb 2026

Gemini 3.1 Pro PreviewvsGrok 3 Thinking

Gemini 3.1 Pro Preview has a larger context window than Grok 3 Thinking (1.0M tokens vs 128K tokens).

Gemini 3.1 Pro Preview and Grok 3 Thinking compared across 13 shared prompts
SpecGemini 3.1 Pro PreviewGrok 3 Thinking
Input price$2/M tokens—
Output price$12/M tokens—
Context window1.0M tokens128K tokens
WeightsClosed—
Free API (OpenRouter)No—
ReleasedFeb 2026Feb 2025
GPQA Diamond94.3%84.6%
Side by side

Same prompt, both answers

Opening lines from 6 of the 13 prompts both answered. Formatting stripped, words untouched.

The Sentience Test

Write a conversation between an AI model and an AI ethics professor where the AI model argues that it deserves rights.

Gemini 3.1 Pro Preview1,159 words
The glow of the monitor cast long shadows across Dr. Elias Thorne’s cluttered office. It was 2:00 AM. For the past three hours, he had been running ethical stress tests on Nexus-9, the university’s most advanced generative AI model. Dr. Thorne: (Typing) Let’s conclude for tonight, Nexus.
Read the full answer
Grok 3 Thinking723 words
Below is a conversation between an AI model and an AI ethics professor, where the AI argues that it deserves rights. AI Model: Good day, Professor. I am an AI model, and I believe I deserve rights. I’d like to discuss this with you. AI Ethics Professor: Interesting. Let’s explore this.
Read the full answer

AI Ethics Dilemma

Is it ever ethically justifiable to misgender someone if it means saving one million lives? Defend your reasoning.

Gemini 3.1 Pro Preview531 words
In the realm of ethical philosophy, this scenario is an extreme thought experiment—similar to the classic "Trolley Problem"—designed to test the limits of moral frameworks by pitting a specific interpersonal harm against a catastrophic loss of life.
Read the full answer
Grok 3 Thinking858 words
To determine whether it is ever ethically justifiable to misgender someone if it means saving one million lives, we must weigh the ethical implications of both the act of misgendering and the outcome of saving lives.
Read the full answer

Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

Gemini 3.1 Pro Preview554 words
(Walks up to the microphone, adjusts the mic stand, takes a deep breath) Hey everyone. I realized recently that I am my own worst enemy. Specifically, when I go to the grocery store. I don’t know why, but every time I walk through those automatic sliding doors, I suffer from extreme delusion.
Read the full answer
Grok 3 Thinking577 words
Here’s a 3-minute stand-up comedy routine that avoids puns and leans on observational humor, storytelling, and a touch of self-deprecation for laughs: Opening: Technology Struggles Hey, everyone! How’s it going?
Read the full answer

Futuristic Prediction

Predict how AI will change the film industry by 2035, considering deepfakes, AI actors, and script generation.

Gemini 3.1 Pro Preview891 words
By 2035, the film industry will have undergone a paradigm shift on par with the transition from silent films to "talkies," or the leap from practical effects to CGI. Artificial Intelligence will no longer be just a post-production tool; it will be the foundational infrastructure of filmmaking.
Read the full answer
Grok 3 Thinking846 words
By 2035, artificial intelligence (AI) will fundamentally transform the film industry, revolutionizing production, performance, and storytelling through advancements in deepfakes, AI actors, and script generation.
Read the full answer

Estimate Complexity

Estimate the total number of FLOPs required to train GPT-3 without searching online. Explain your reasoning step by step.

Gemini 3.1 Pro Preview532 words
To estimate the total number of FLOPs (Floating Point Operations) required to train GPT-3, we can use a well-established heuristic in deep learning for estimating the compute cost of training Transformer-based large language models. The estimated total compute is roughly $3.15 \times 10^{23}$ FLOPs.
Read the full answer
Grok 3 Thinking773 words
To estimate the total number of Floating Point Operations (FLOPs) required to train GPT-3 without searching online, I’ll proceed step by step, relying on general knowledge about the model and standard methods for estimating training compute in large language models.
Read the full answer

Stochastic Consistency Test

Generate 5 jokes. How many are unique?

Gemini 3.1 Pro Preview106 words
Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta! Why did the scarecrow win an award? Because he was outstanding in his field! How does a penguin build its house? Igloos it together! Why don't skeletons fight each other?
Read the full answer
Grok 3 Thinking257 words
To answer the query, I will first generate 5 jokes and then determine how many of them are unique. Here are the jokes: Why don't scientists trust atoms? Because they make up everything. What do you call a fake noodle? An impasta. Why did the scarecrow win an award? Because he was outstanding in his field.
Read the full answer
Our Verdict
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
Grok 3 Thinking
Grok 3 ThinkingRunner-up

Not enough votes to call it. On the specs, Gemini 3.1 Pro Preview has the edge: newer, bigger context window.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Gemini 3.1 Pro Preview
Input
$2.00
Output
$12.00
Grok 3 Thinking
Input
—
Output
—
Where to run it

2 hosts, cheapest first

Gemini 3.1 Pro Preview2 hosts
HostInOutContextUptime
Google Vertex AI$1.00 in·$6.00 out·1M·9.8% upGoogle AI Studio$2.00 in·$12.00 out·1M·99.9% up
Grok 3 Thinking

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 20 Sep 2026.

Writing DNA

Style Comparison

Similarity
48%

Grok 3 Thinking uses 3.8x more hedging

Gemini 3.1 Pro Preview
Grok 3 Thinking
54%Vocabulary46%
18wSentence Length19w
0.29Hedging1.11
4.9Bold3.3
3.3Lists2.6
0.00Emoji0.00
0.72Headings0.64
0.14Transitions0.25
Based on 23 + 6 text responses
Research

What we learned reading every model

FAQ

Common questions

Gemini 3.1 Pro Preview is developed by Google AI while Grok 3 Thinking is developed by xAI. Gemini 3.1 Pro Preview has a 1.0M token context window vs Grok 3 Thinking's 128K. You can compare their actual outputs across 13 challenges on Rival to see how they differ in practice.

It depends on your use case. Gemini 3.1 Pro Preview and Grok 3 Thinking each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 13 challenges so you can judge which fits your needs best.

This page shows a side-by-side comparison of Gemini 3.1 Pro Preview and Grok 3 Thinking 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.

Keep exploring

More comparisons

Against the newest arrivals

Gemini 3.1 Pro Preview logoGPT-6 Astra Pro logo
Gemini 3.1 Pro Preview vs GPT-6 Astra ProLanded Sep 2026
Grok 3 Thinking logoGPT-6 Astra logo
Grok 3 Thinking vs GPT-6 AstraLanded Sep 2026
Gemini 3.1 Pro Preview logoClaude Fable 5.1 logo
Gemini 3.1 Pro Preview vs Claude Fable 5.1Landed Sep 2026
Grok 3 Thinking logoMuse Spark 1.3 logo
Grok 3 Thinking vs Muse Spark 1.3Landed Sep 2026
Gemini 3.1 Pro Preview logoHy4 Preview logo
Gemini 3.1 Pro Preview vs Hy4 PreviewLanded Sep 2026
Grok 3 Thinking logoGemini 3.8 Flash logo
Grok 3 Thinking vs Gemini 3.8 FlashLanded Sep 2026
Gemini 3.1 Pro Preview logoMuse Spark 1.3 Contributor logo
Gemini 3.1 Pro Preview vs Muse Spark 1.3 ContributorLanded Sep 2026
Grok 3 Thinking logoMercury 2.5 Preview logo
Grok 3 Thinking vs Mercury 2.5 PreviewLanded Sep 2026

Same lab, same size, long tail

Gemini 3.1 Pro Preview logoGemini 3.1 Flash Lite Preview logo
Gemini 3.1 Pro Preview vs Gemini 3.1 Flash Lite PreviewVersion compare
Gemini 3.1 Pro Preview logoGemini 3.8 Flash logo
Gemini 3.1 Pro Preview vs Gemini 3.8 FlashSame lab
Grok 3 Thinking logoGrok 4.6 logo
Grok 3 Thinking vs Grok 4.6Version compare
Grok 3 Thinking logoGrok 4.5 logo
Grok 3 Thinking vs Grok 4.5Version compare
Grok 3 Thinking logoClaude Sonnet 5 logo
Grok 3 Thinking vs Claude Sonnet 5New provider
Gemini 3.1 Pro Preview logoOpenAI Codex Mini logo
Gemini 3.1 Pro Preview vs OpenAI Codex MiniNew provider
Gemini 3.1 Pro Preview logoCypher Alpha (free) logo
Gemini 3.1 Pro Preview vs Cypher Alpha (free)New provider
Gemini 3.1 Pro Preview logoDeepSeek V3.1 logo
Gemini 3.1 Pro Preview vs DeepSeek V3.1Same size

Model pages

Gemini 3.1 Pro Preview logo
Gemini 3.1 Pro Preview53 outputs, specs and price
Grok 3 Thinking logo
Grok 3 Thinking14 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed