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
  • Default Index
  • 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. Grok 4.1 FastvsNex-N2.5-Pro (free)
Updated Sep 2026

Grok 4.1 FastvsNex-N2.5-Pro (free)

Nex-N2.5-Pro (free) is the newer model, released after Grok 4.1 Fast.

Grok 4.1 Fast and Nex-N2.5-Pro (free) compared across 14 shared prompts
SpecGrok 4.1 FastNex-N2.5-Pro (free)
Input price—Free
Output price—Free
Context window—262K tokens
Free API (OpenRouter)NoYes (1 provider)
ReleasedNov 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 14 prompts both answered. Formatting stripped, words untouched.

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)…
Read the full answer
Nex-N2.5-Pro (free)119 words
Pantry Moon Bars A sweet, chewy peanut butter–chocolate oat treat made with only 7 pantry staples. Ingredients Rolled oats Creamy peanut butter Honey Chocolate chips Vanilla extract Ground cinnamon Salt Instructions Heat oven to 350°F / 175°C. Line an 8-inch square pan with parchment paper.
Read the full answer

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
Nex-N2.5-Pro (free)2,451 words
Below is a general contract-risk review, not legal advice. Enforceability depends heavily on jurisdiction, contractor classification, and the exact facts. Also, even if a clause might be unenforceable, relying on that is risky because litigation/arbitration is expensive.
Read the full answer

Historical Counterfactual Analysis

If the transistor had been invented in 1920 instead of 1947, trace the likely technological, economic, and geopolitical implications through…

Grok 4.1 Fast922 words
Technological Implications Immediate Advancements (1920s-1930s): Transistors replace bulky, power-hungry vacuum tubes by mid-1920s. Radios become pocket-sized and cheap by 1925 (vs. 1954 historically), accelerating mass media.
Read the full answer
Nex-N2.5-Pro (free)2,726 words
Starting assumption Assume the 1920 “transistor” is a usable but crude solid-state amplifier/switch: reproducible enough for telecom and radio, but noisy, low-power, temperature-sensitive, and expensive at first.
Read the full answer

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 4.1 Fast555 words
1-Month Plan for Better Health and Longevity This beginner-friendly plan focuses on three foundational areas: Diet, Exercise, and Sleep. These pillars drive longevity by reducing inflammation, building resilience, and optimizing recovery. Commit to small, consistent changes—aim for 80% adherence.
Read the full answer
Nex-N2.5-Pro (free)518 words
1-Month Beginner Health & Longevity Plan Goal: Build simple habits you can keep—not perfection. Focus on 3 areas: diet, exercise, and sleep/stress. Diet: Eat for steady energy Week 1: Add before you subtract Add 1 fruit or vegetable to 2 meals per day. Drink a glass of water when you wake up and before meals.
Read the full answer

Michelin Star Recipe Design

Design an innovative recipe for a multi-component dish worthy of a Michelin 3-star restaurant. The recipe should feature an unusual…

Grok 4.1 Fast1,041 words
Lunar Tide Conceptual Narrative Lunar Tide captures the mesmerizing interplay between celestial forces and oceanic depths, where the moon's pale luminescence tugs at the sea's primordial pulse.
Read the full answer
Nex-N2.5-Pro (free)1,665 words
Dish: “Tidewater Orchard” Langoustine · Mirabelle Plum · Juniper · Kombu · Rye A tasting-menu course built around an unusual pairing: sweet cold-water langoustine with mirabelle plum, bridged by kombu umami, juniper resin, green tomato acidity, and toasted rye bitterness.
Read the full answer

Startup Pitch Teardown

Here's a pitch deck summary for a startup called "MindMeld AI": **Slide 1 - Vision:** "We're building the future of human-AI collaboration.…

Grok 4.1 Fast501 words
Solution Claim: "94% accuracy" for decoding neural patterns into text via EEG headband Why it's weak: This is by far the most exaggerated technical claim, as current non-invasive EEG-based brain-computer interfaces (BCIs) for text generation achieve nowhere near 94% accuracy in real-world conditions.
Read the full answer
Nex-N2.5-Pro (free)593 words
The 3 weakest claims are the ones most likely to be challenged in diligence: Weakest claim Why it’s weak How to strengthen it 1. “94% accuracy… works with any language, any device.” This is the biggest scientific and product credibility risk.
Read the full answer
Our Verdict
Grok 4.1 Fast
Grok 4.1 Fast
Nex-N2.5-Pro (free)
Nex-N2.5-Pro (free)Runner-up

Not enough votes to call it. On the specs, Grok 4.1 Fast has the edge: bigger model tier, major provider backing.

Too close to call
API pricing

Cost per 1M tokens

Grok 4.1 Fast
Input
—
Output
—
Nex-N2.5-Pro (free)
Input
$0.000
Output
$0.000
Where to run it

1 host

Grok 4.1 Fast

No hosts listed on OpenRouter.

Nex-N2.5-Pro (free)1 host
HostInOutContextUptime
NNex AGIfp8degraded$0 in·$0 out·262k·99.2% up

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Grok 4.1 Fast is developed by xAI while Nex-N2.5-Pro (free) is developed by Nex AGI. You can compare their actual outputs across 14 challenges on Rival to see how they differ in practice.

It depends on your use case. Grok 4.1 Fast and Nex-N2.5-Pro (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 14 challenges so you can judge which fits your needs best.

This page shows a side-by-side comparison of Grok 4.1 Fast and Nex-N2.5-Pro (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.

Keep exploring

More comparisons

Against the newest arrivals

Grok 4.1 Fast logoDeepSeek V4 Flash Vision Exp logo
Grok 4.1 Fast vs DeepSeek V4 Flash Vision ExpLanded Sep 2026
Nex-N2.5-Pro (free) logoSolar Pro 4 logo
Nex-N2.5-Pro (free) vs Solar Pro 4Landed Sep 2026
Grok 4.1 Fast logoHy3 logo
Grok 4.1 Fast vs Hy3Landed Sep 2026
Nex-N2.5-Pro (free) logoQwen3.7 Flash logo
Nex-N2.5-Pro (free) vs Qwen3.7 FlashLanded Sep 2026
Grok 4.1 Fast logoLing 3.0 Flash logo
Grok 4.1 Fast vs Ling 3.0 FlashLanded Sep 2026
Nex-N2.5-Pro (free) logoMuse Glimmer 30B logo
Nex-N2.5-Pro (free) vs Muse Glimmer 30BLanded Sep 2026
Grok 4.1 Fast logoGLM 5.3 logo
Grok 4.1 Fast vs GLM 5.3Landed Sep 2026
Nex-N2.5-Pro (free) logoTernary Bonsai 2 27B logo
Nex-N2.5-Pro (free) vs Ternary Bonsai 2 27BLanded Sep 2026

Same lab, same size, long tail

Grok 4.1 Fast logoGrok 4.7 logo
Grok 4.1 Fast vs Grok 4.7Same lab
Grok 4.1 Fast logoGrok 4.6 logo
Grok 4.1 Fast vs Grok 4.6Same lab
Nex-N2.5-Pro (free) logoNex-N2.5-Mini (free) logo
Nex-N2.5-Pro (free) vs Nex-N2.5-Mini (free)Same lab
Nex-N2.5-Pro (free) logoOx Alpha logo
Nex-N2.5-Pro (free) vs Ox AlphaSame size
Grok 4.1 Fast logoGLM 5.3 Flash logo
Grok 4.1 Fast vs GLM 5.3 FlashNew provider
Grok 4.1 Fast logoGLM 5.3 FlashX logo
Grok 4.1 Fast vs GLM 5.3 FlashXNew provider
Nex-N2.5-Pro (free) logoGolden Gate Claude logo
Nex-N2.5-Pro (free) vs Golden Gate ClaudeSame size
Nex-N2.5-Pro (free) logoGPT-3.5 Turbo logo
Nex-N2.5-Pro (free) vs GPT-3.5 TurboNew provider

Model pages

Grok 4.1 Fast logo
Grok 4.1 Fast59 outputs, specs and price
Nex-N2.5-Pro (free) logo
Nex-N2.5-Pro (free)14 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
  • Default Index
  • 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