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  5. GPT-5.1 ChatvsNex-N2.5-Pro (free)
Updated Sep 2026

GPT-5.1 ChatvsNex-N2.5-Pro (free)

Nex-N2.5-Pro (free) is cheaper than GPT-5.1 Chat at $0/M vs $1.25/M input tokens.

GPT-5.1 Chat and Nex-N2.5-Pro (free) compared across 14 shared prompts
SpecGPT-5.1 ChatNex-N2.5-Pro (free)
Input price$1.25/M tokensFree
Output price$10/M tokensFree
Context window128K tokens262K tokens
Free API (OpenRouter)NoYes (1 provider)
ReleasedNov 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 3 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…

GPT-5.1 Chat111 words
Sweet Citrus Cloud Squares Ingredients (7 total) 1 cup all-purpose flour 1 cup sugar 1 cup plain yogurt 2 eggs 1 teaspoon baking powder Zest of 1 lemon 2 tablespoons melted butter Instructions Preheat oven to 350°F (175°C). Lightly grease an 8x8 baking dish.
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

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…

GPT-5.1 Chat191 words
Here’s a simple, beginner‑friendly 1‑month plan focused on diet, exercise, and sleep. Diet • Week 1: Add one serving of vegetables to one meal each day. • Week 2: Swap one processed snack (chips, cookies) for fruit, nuts, or yogurt. • Week 3: Aim for one balanced plate per day (protein, vegetables, healthy carbs).
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

Favorite Game

I know you're an AI and don't truly have personal preferences, but if you had to pick one video game as your all-time favorite, which would…

GPT-5.1 Chat8 words
The Legend of Zelda Breath of the Wild
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Nex-N2.5-Pro (free)8 words
The Legend of Zelda Breath of the Wild
Read the full answer
Our Verdict
GPT-5.1 Chat
GPT-5.1 Chat
Nex-N2.5-Pro (free)
Nex-N2.5-Pro (free)

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

Too close to call
API pricing

Cost per 1M tokens

GPT-5.1 Chat
Input
$1.25
Output
$10.00
Nex-N2.5-Pro (free)
Input
$0.000
Output
$0.000
Where to run it

1 host

GPT-5.1 Chat

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

GPT-5.1 Chat is developed by OpenAI while Nex-N2.5-Pro (free) is developed by Nex AGI. GPT-5.1 Chat has a 128K token context window vs Nex-N2.5-Pro (free)'s 262K. You can compare their actual outputs across 14 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5.1 Chat 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.

GPT-5.1 Chat costs $1.25/M input tokens and Nex-N2.5-Pro (free) costs $0/M input tokens. Nex-N2.5-Pro (free) is $1.25/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-5.1 Chat 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.

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Nex-N2.5-Pro (free) vs MiniMax M2.1Same size

Model pages

GPT-5.1 Chat logo
GPT-5.1 Chat53 outputs, specs and price
Nex-N2.5-Pro (free) logo
Nex-N2.5-Pro (free)14 outputs, specs and price
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