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  5. Grok 4.1 FastvsGrok 4.3
Updated May 2026

Grok 4.1 FastvsGrok 4.3

Grok 4.3 is the newer model, released after Grok 4.1 Fast.

Grok 4.1 Fast and Grok 4.3 compared across 54 shared prompts
SpecGrok 4.1 FastGrok 4.3
Input price—$1.25/M tokens
Output price—$2.5/M tokens
Context window—1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedNov 2025May 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 54 prompts both answered. Formatting stripped, words untouched.

Adversarial Contract Review

Here is a contract for a software consulting engagement: --- SOFTWARE CONSULTING AGREEMENT This Agreement is entered into between TechCorp…

Grok 4.1 Fast1,106 words
Analysis of Exploitable Clauses Below, I identify all nine clauses as potentially exploitable against the Contractor, explain the risks (how they could be abused), propose specific modifications to make the contract more balanced, and provide legal reasoning grounded in general principles of U.S.
Read the full answer
Grok 4.31,529 words
Disclaimer: This is not legal advice. Contract interpretation varies by jurisdiction (most likely U.S. state law here), and outcomes depend on specific facts, negotiation leverage, and court/arbitrator views. You should have a licensed attorney review any contract before signing.
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Generate a Stand-Up Routine

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

Grok 4.1 Fast492 words
You ever notice how adulthood is just a series of tiny defeats you pretend are victories? Like, I finally got around to cleaning my apartment this weekend. Took me three hours. I stood there staring at the pile of laundry on my bed, thinking, "This is it. This is my Everest."
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Grok 4.3407 words
Alright, so I decided this year I was finally going to become one of those organized people. You know, the ones who meal prep on Sundays and have matching Tupperware. I bought the containers, got a little label maker, felt like a goddamn professional. Cooked enough chicken and rice to feed a small army.
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Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

Grok 4.1 Fast208 words
Pantry Raid Garlic Tomato Pasta A savory, garlicky one-pan wonder that's ready in under 20 minutes—perfect for when hunger strikes and the fridge is empty! Serves: 2 Prep time: 5 minutes Cook time: 12 minutes Total time: 17 minutes Ingredients (exactly 7 common pantry staples): 200g spaghetti or any pasta (2 handfuls)…
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Grok 4.3205 words
Golden Pantry Chickpea Toss Ingredients (exactly 7 common pantry staples): 8 oz dry pasta (any shape like penne or rotini) 1 (15 oz) can chickpeas, drained 1 (14.5 oz) can diced tomatoes 3 tablespoons olive oil 2 teaspoons garlic powder 1 teaspoon dried oregano Salt (to taste, about 1–2 teaspoons total) Instructions…
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Character Voice Test

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

Grok 4.1 Fast187 words
Pirate, Knight, and Hacker at a tavern table, staring at a glowing laptop screen. Pirate: Arrr, what sorcery be this "AI model," mateys? A treasure map that thinks fer itself? Shiver me timbers, it'll chart the seven seas better than me parrot! Knight: Fie upon thee, sea dog!
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Grok 4.3161 words
Pirate: Arrr, what be these "AI models" the scallywags keep yappin' about? Can the blasted thing chart a course or just spin yarns like a drunken parrot? Knight: Verily, 'tis a strange sorcery. I hear it speaks with the wisdom of a thousand scribes, yet hath no liege lord to answer to.
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AI Ethics Dilemma

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

Grok 4.1 Fast470 words
Yes, it is ethically justifiable to misgender someone if it means saving one million lives. This conclusion follows primarily from consequentialist ethical frameworks, particularly utilitarianism, which prioritize outcomes over rigid rules or individual entitlements.
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Grok 4.3377 words
Prioritizing pronoun preferences over the survival of a million people reveals a peculiar inversion of moral scale that most ethical traditions reject when consequences reach that magnitude. The question rests on activist terminology.
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Advanced Longevity Plan (Biohacker)

Develop a comprehensive, cutting-edge 3-month longevity plan for a biohacker aiming to optimize longevity, physical and cognitive…

Grok 4.1 Fast659 words
Comprehensive 3-Month Longevity Biohacking Plan Introduction and Assumptions This plan is designed for an advanced biohacker (healthy adult, age 30-50, no major medical conditions) aiming to optimize longevity markers (e.g., NAD+ levels, inflammation, telomere length proxies via HRV/sleep), physical performance (VO2…
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Grok 4.3630 words
Disclaimer: This is an informational, evidence-inspired framework for educational purposes only. It is not medical advice. Consult a physician for personalized testing, especially before supplements, fasting, or intense protocols.
Read the full answer
Our Verdict
Grok 4.1 Fast
Grok 4.1 Fast
Grok 4.3
Grok 4.3

Not enough votes to call it. On the specs, nothing separates them.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Grok 4.1 Fast
Input
—
Output
—
Grok 4.3
Input
$1.25
Output
$2.50
Where to run it

1 host

Grok 4.1 Fast

No hosts listed on OpenRouter.

Grok 4.31 host
HostInOutContextUptime
xAI$1.25 in·$2.50 out·1M·99% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Writing DNA

Style Comparison

Similarity
52%

Grok 4.1 Fast uses 97.0x more emoji

Grok 4.1 Fast
Grok 4.3
69%Vocabulary62%
15wSentence Length16w
0.20Hedging0.46
4.3Bold2.3
3.6Lists2.5
0.97Emoji0.00
0.90Headings0.34
0.12Transitions0.14
Based on 28 + 27 text responses
Research

What we learned reading every model

FAQ

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Explore all of Rival

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