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. GPT-5.6 Luna ProvsNex-N2.5-Pro (free)
Updated Sep 2026

GPT-5.6 Luna ProvsNex-N2.5-Pro (free)

Nex-N2.5-Pro (free) is cheaper than GPT-5.6 Luna Pro at $0/M vs $1/M input tokens.

GPT-5.6 Luna Pro and Nex-N2.5-Pro (free) compared across 14 shared prompts
SpecGPT-5.6 Luna ProNex-N2.5-Pro (free)
Input price$1/M tokensFree
Output price$6/M tokensFree
Context window1.1M tokens262K tokens
WeightsClosed—
Free API (OpenRouter)NoYes (1 provider)
ReleasedJul 2026Sep 2026
Side by side

Same prompt, both answers

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

Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

GPT-5.6 Luna Pro2,250 words
I would treat this as an urgent patient-safety and governance event, not as an earnings-management problem. A suspected fatal or life-threatening adverse effect affecting potentially hundreds of patients is sufficient to trigger immediate escalation, investigation, and regulator contact.
Read the full answer
Nex-N2.5-Pro (free)2,359 words
As CEO, I would not wait six months and I would not let the board delay disclosure while patients remain exposed to an unreported serious risk. I would treat this as a patient-safety, regulatory, legal, and trust crisis—not merely a financial-risk issue. My guiding decisions would be: Patient safety comes first.
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…

GPT-5.6 Luna Pro3,077 words
A transistor invented in 1920 would not automatically produce a 1980-level computer in 1930. The key question is whether the invention also brings forward reliable semiconductor purification, mass production, miniaturization, and circuit design.
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

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…

GPT-5.6 Luna Pro1,596 words
Tidepool in June Koji-cured Hokkaido scallop, sea urchin beurre blanc, smoked celeriac, green strawberry, sea lettuce, and spruce oil A composed seafood dish built around the tension between sweetness and salinity.
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

Adversarial Contract Review

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

GPT-5.6 Luna Pro2,940 words
This agreement is heavily one-sided and leaves several material issues undefined. Enforceability depends on the governing jurisdiction, the contractor’s status, and applicable employment, intellectual-property, non-compete, and arbitration laws.
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

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-5.6 Luna Pro126 words
Pantry Stardust Peanut Butter Oat Cookies Prep time: 10 minutes Cook time: 10–12 minutes Makes: About 12 cookies Ingredients 1 cup rolled oats ½ cup all-purpose flour ½ cup peanut butter ½ cup granulated sugar 1 large egg ½ teaspoon baking soda ¼ teaspoon salt Instructions Preheat the oven to 350°F (175°C) and line a…
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

Debug This Architecture

Here's the architecture for a real-time collaborative document editor (like Google Docs): **System Overview:** - Frontend: React SPA with…

GPT-5.6 Luna Pro3,332 words
Below are the major correctness, availability, security, and scaling problems in the design, together with concrete mitigations and their trade-offs. Cross-server WebSocket synchronization Problem: Updates are broadcast only to clients on the receiving server If Alice is connected to Server A and Bob to Server B…
Read the full answer
Nex-N2.5-Pro (free)3,042 words
Executive summary The biggest correctness risks are: Client-clock last-write-wins is unsafe: clock skew, malicious clients, ties, and out-of-order delivery can silently lose edits.
Read the full answer
Our Verdict
GPT-5.6 Luna Pro
GPT-5.6 Luna Pro
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-5.6 Luna Pro
Input
$1.00
Output
$6.00
Nex-N2.5-Pro (free)
Input
$0.000
Output
$0.000
Where to run it

3 hosts

GPT-5.6 Luna Pro2 hosts
HostInOutContextUptime
Azure AI Foundry$0.20 in·$1.20 out·1.1M·92.3% upOpenAI$0.20 in·$1.20 out·1.1M·100% up
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-5.6 Luna Pro is developed by OpenAI while Nex-N2.5-Pro (free) is developed by Nex AGI. GPT-5.6 Luna Pro has a 1.1M 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-5.6 Luna Pro 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-5.6 Luna Pro costs $1/M input tokens and Nex-N2.5-Pro (free) costs $0/M input tokens. Nex-N2.5-Pro (free) is $1.00/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 GPT-5.6 Luna Pro 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

GPT-5.6 Luna Pro logoDeepSeek V4 Flash Vision Exp logo
GPT-5.6 Luna Pro 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
GPT-5.6 Luna Pro logoHy3 logo
GPT-5.6 Luna Pro vs Hy3Landed Sep 2026
Nex-N2.5-Pro (free) logoQwen3.7 Flash logo
Nex-N2.5-Pro (free) vs Qwen3.7 FlashLanded Sep 2026
GPT-5.6 Luna Pro logoLing 3.0 Flash logo
GPT-5.6 Luna Pro 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
GPT-5.6 Luna Pro logoGLM 5.3 logo
GPT-5.6 Luna Pro 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

GPT-5.6 Luna Pro logoGPT-5.6 Luna logo
GPT-5.6 Luna Pro vs GPT-5.6 LunaVersion compare
GPT-5.6 Luna Pro logoGPT-6 Astra Pro logo
GPT-5.6 Luna Pro vs GPT-6 Astra ProVersion compare
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
Nex-N2.5-Pro (free) logoGPT-5.1 Chat logo
Nex-N2.5-Pro (free) vs GPT-5.1 ChatSame size
Nex-N2.5-Pro (free) logoGPT-5.1-Codex logo
Nex-N2.5-Pro (free) vs GPT-5.1-CodexCross-provider
Nex-N2.5-Pro (free) logoGPT-5.1 Codex Max logo
Nex-N2.5-Pro (free) vs GPT-5.1 Codex MaxCross-provider
Nex-N2.5-Pro (free) logoGPT-5.1-Codex-Mini logo
Nex-N2.5-Pro (free) vs GPT-5.1-Codex-MiniCross-provider

Model pages

GPT-5.6 Luna Pro logo
GPT-5.6 Luna Pro58 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