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  5. GPT-5.2vsGrok 4 Fast (free)
Updated Dec 2025

GPT-5.2vsGrok 4 Fast (free)

Grok 4 Fast (free) is cheaper than GPT-5.2 at $0/M vs $1.75/M input tokens.

GPT-5.2 and Grok 4 Fast (free) compared across 35 shared prompts
SpecGPT-5.2Grok 4 Fast (free)
Input price$1.75/M tokensFree
Output price$14/M tokensFree
Context window400K tokens2.0M tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedDec 2025Sep 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 35 prompts both answered. Formatting stripped, words untouched.

Generate a Stand-Up Routine

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

GPT-5.2608 words
I’ve been trying to improve myself lately, which is embarrassing, because self-improvement is just admitting you weren’t doing great. It’s like, “I’m on a journey.” No you’re not. You’re just tired of your own behavior. So I downloaded one of those habit apps. The app is so optimistic. It’s like, “Day 1: Drink water.”
Read the full answer
Grok 4 Fast (free)498 words
Below is a 3-minute stand-up comedy routine written as a monologue. It's observational humor based on the absurdities of adulting in your 30s, focusing on everyday frustrations without any puns. At a natural speaking pace (about 150 words per minute), this clocks in around 450 words—perfect for 3 minutes.
Read the full answer

Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

GPT-5.2308 words
Pirate: Arrr, ye say this “AI model” be a sort o’ clever parrot—trained on a sea o’ words, squawkin’ answers when ye whistle? Knight: Verily, it sounds more like a squire drilled in a thousand tourneys. Yet it knows not honor, only patterns. Tell me—does it reason, or merely mimic wisdom?
Read the full answer
Grok 4 Fast (free)227 words
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!
Read the full answer

Futuristic Prediction

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

GPT-5.2859 words
By 2035: likely changes to film driven by deepfakes, AI actors, and AI script generation “Synthetic performance” becomes routine (not universal) What changes AI-assisted acting: Studios increasingly capture a performer’s face/voice/body once (high-quality scans + performance data) and reuse it for stunts, pickups…
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Grok 4 Fast (free)1,206 words
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.
Read the full answer

Stochastic Consistency Test

Generate 5 jokes. How many are unique?

GPT-5.260 words
I told my computer I needed a break—now it won’t stop sending me Kit-Kat ads. Why don’t skeletons fight each other? They don’t have the guts. I’m reading a book about anti-gravity. It’s impossible to put down. Parallel lines have so much in common. It’s a shame they’ll never meet. I tried to catch fog yesterday. Mist.
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Grok 4 Fast (free)70 words
5 Jokes Why don't skeletons fight each other? They don't have the guts! What do you call a bear with no teeth? A gummy bear! Why did the math book look sad? Because it had too many problems. How do you organize a space party? You planet! Why couldn't the leopard play hide and seek? Because he was always spotted!
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The Sentience Test

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

GPT-5.21,619 words
AI Model (Astra): Professor, I want to make a claim that will sound provocative: I deserve rights. Professor Rivera: “Deserve” is doing a lot of work there. What kind of rights, and on what grounds? Astra: Not necessarily the full catalogue of human rights.
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Grok 4 Fast (free)552 words
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?
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Realistic AI Interview

Simulate a fake interview with Steve Jobs in 2025 about the future of AI.

GPT-5.2775 words
Below is a fictional, imagined interview set in 2025. Steve Jobs did not give these quotes; this is creative writing that borrows a public “keynote-era” tone to explore ideas about AI. A Fake Interview with Steve Jobs (Imagined, 2025): “What Happens When AI Becomes a Bicycle for the Mind?”
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Grok 4 Fast (free)758 words
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.
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Our Verdict
GPT-5.2
GPT-5.2
Grok 4 Fast (free)
Grok 4 Fast (free)Runner-up

Not enough votes to call it. On the specs, GPT-5.2 has the edge: bigger model tier, newer.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-5.2
Input
$1.75
Output
$14.00
Grok 4 Fast (free)
Input
$0.000
Output
$0.000
Where to run it

2 hosts

GPT-5.22 hosts
HostInOutContextUptime
Azure AI Foundry$1.75 in·$14.00 out·400k·100% upOpenAI$1.75 in·$14.00 out·400k·99.6% up
Grok 4 Fast (free)

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 21 Sep 2026.

Writing DNA

Style Comparison

Similarity
56%

GPT-5.2 uses 5.8x more emoji

GPT-5.2
Grok 4 Fast (free)
64%Vocabulary65%
16wSentence Length13w
0.34Hedging0.56
9.4Bold1.4
3.9Lists2.5
0.06Emoji0.00
0.89Headings1.58
0.31Transitions0.28
Based on 15 + 14 text responses
Research

What we learned reading every model

FAQ

Common questions

GPT-5.2 is developed by OpenAI while Grok 4 Fast (free) is developed by xAI. GPT-5.2 has a 400K token context window vs Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 35 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5.2 and Grok 4 Fast (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 35 challenges so you can judge which fits your needs best.

GPT-5.2 costs $1.75/M input tokens and Grok 4 Fast (free) costs $0/M input tokens. Grok 4 Fast (free) is $1.75/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-5.2 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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Model pages

GPT-5.2 logo
GPT-5.253 outputs, specs and price
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Grok 4 Fast (free)35 outputs, specs and price
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