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  5. Grok 4 Fast (free)vsQwen3.8 Max Prime
Updated Sep 2026

Grok 4 Fast (free)vsQwen3.8 Max Prime

Grok 4 Fast (free) is cheaper than Qwen3.8 Max Prime at $0/M vs $4/M input tokens.

Grok 4 Fast (free) and Qwen3.8 Max Prime compared across 2 shared prompts
SpecGrok 4 Fast (free)Qwen3.8 Max Prime
Input priceFree$4/M tokens
Output priceFree$12/M tokens
Context window2.0M tokens1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedSep 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from every prompt both answered. Formatting stripped, words untouched.

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

Grok 4 Fast (free)849 words
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.
Read the full answer
Qwen3.8 Max Prime473 words
Your 1-Month Foundation Plan A simple, progressive plan built on three pillars. Each week, you add one small layer. No perfection required—just consistency. 🏃 Pillar 1: Movement Why: Even modest activity reduces all-cause mortality risk and improves mood, sleep, and energy within days.
Read the full answer

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 Fast (free)240 words
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.
Read the full answer
Qwen3.8 Max Prime223 words
🍯 Golden Hour Noodles A sweet, savory, garlicky pasta that tastes like it took way more effort than it did. Ingredients (7) # Ingredient Amount 1 Spaghetti 8 oz (half a box) 2 Butter 3 tablespoons 3 Garlic, minced 4 cloves 4 Honey 2 tablespoons 5 Soy sauce 1 tablespoon 6 Red pepper flakes ½ teaspoon 7 Parmesan cheese…
Read the full answer
Our Verdict
Grok 4 Fast (free)
Grok 4 Fast (free)
Qwen3.8 Max Prime
Qwen3.8 Max Prime

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

Too close to call
API pricing

Cost per 1M tokens

Grok 4 Fast (free)
Input
$0.000
Output
$0.000
Qwen3.8 Max Prime
Input
$4.00
Output
$12.00
Where to run it

1 host

Grok 4 Fast (free)

No hosts listed on OpenRouter.

Qwen3.8 Max Prime1 host
HostInOutContextUptime
Alibaba Cloud$4.00 in·$12.00 out·1M·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Grok 4 Fast (free) is developed by xAI while Qwen3.8 Max Prime is developed by Qwen. Grok 4 Fast (free) has a 2.0M token context window vs Qwen3.8 Max Prime's 1.0M. You can compare their actual outputs across 2 challenges on Rival to see how they differ in practice.

It depends on your use case. Grok 4 Fast (free) and Qwen3.8 Max Prime each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 2 challenges so you can judge which fits your needs best.

Grok 4 Fast (free) costs $0/M input tokens and Qwen3.8 Max Prime costs $4/M input tokens. Grok 4 Fast (free) is $4.00/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 Grok 4 Fast (free) and Qwen3.8 Max Prime 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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