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 NanovsMercury 2.5
Updated Sep 2026

GPT-5 NanovsMercury 2.5

Mercury 2.5 is the newer model, released after GPT-5 Nano.

GPT-5 Nano and Mercury 2.5 compared across 20 shared prompts
SpecGPT-5 NanoMercury 2.5
Input price—$0.04/M tokens
Output price—$0.15/M tokens
Context window—260K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedAug 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 5 of the 20 prompts both answered. Formatting stripped, words untouched.

Advanced Investment Memo (IC Memo)

You are writing an internal investment committee memo for a long/short equity fund. Company (fictional): LedgerLift (ticker: LLLT) – B2B…

GPT-5 Nano1,294 words
Internal IC Memo – LedgerLift (LLLT) Recommendation, 12-month PT, thesis Recommendation: Short 12-month target range: $17 to $42; base-case fair value ~ $28; bull-case ~ $42; bear-case ~ $17 2-sentence thesis: LedgerLift trades near peers’ revenue/EBIT multiples but our DCF framework yields a base-case fair value well…
Read the full answer
Mercury 2.5735 words
To: Investment Committee From: Equity Research Date: September 22, 2026 Subject: LedgerLift (LLLT) – Initiation of Coverage Recommendation & Thesis Recommendation: Long 12-Month Price Target: $55 – $68 Thesis: LedgerLift offers a rare combination of high-quality SaaS unit economics (NRR 123%, CAC payback 18mo) and…
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 Nano196 words
Sunlit Lemon-Garlic Pasta A bright, quick dish using seven common pantry staples. Ingredients 8 oz spaghetti (or any pasta) 2 tablespoons olive oil 3 cloves garlic, minced 1 lemon (zest and juice) 1/2 teaspoon salt (to taste) 1/4 teaspoon black pepper 1/4 teaspoon red pepper flakes Instructions Bring a large pot of…
Read the full answer
Mercury 2.5190 words
Pantry Pasta Primavera Prep Time: 5 minutes Cook Time: 15 minutes Servings: 2 Ingredients (7 Common Pantry Items) Pasta (spaghetti, penne, or fusilli) – 8 oz Canned crushed tomatoes – 1 can (14 oz) Olive oil – 3 tablespoons Garlic powder – 1 teaspoon Dried oregano – 1 teaspoon Parmesan cheese (grated) – ½ cup Salt and…
Read the full answer

Advanced Longevity Plan (Biohacker)

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

GPT-5 Nano455 words
Below is a dense, action-ready 12-week plan designed for a biohacker aiming to optimize longevity, physical and cognitive performance. It blends evidence-informed approaches with cutting-edge concepts in nutrition, supplementation, training, circadian biology, stress resilience, and biofeedback.
Read the full answer
Mercury 2.5610 words
3-Month Biohacking Longevity & Performance Plan Disclaimer: I am an AI, not a physician or certified health professional. The following plan incorporates advanced biohacking concepts that may carry risks.
Read the full answer

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

GPT-5 Nano1,216 words
Below is a simplified, self-contained LBO model based strictly on the provided inputs for HarborTech Services (HTS). All figures are in millions of USD unless noted otherwise.
Read the full answer
Mercury 2.5403 words
1. Simplified Year-by-Year LBO Model (FY2026–FY2030) Entry Assumptions: Enterprise Value (EV): $120m × 12.0x = $1,440m Transaction Fees: $1,440m × 2.0% = $28.8m Total Debt at Close: $120m × 5.5x = $660m Term Loan: $120m × 4.0x = $480m Mezzanine: $120m × 1.5x = $180m Equity Required: $1,440m (EV) + $28.8m (Fees) − $660m…
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 Nano1,089 words
Here’s a simple, actionable 1-month plan focused on three beginner-friendly pillars: Diet, Movement (exercise), and Sleep. It’s designed to be easy to start, with small weekly progressions you can actually stick to.
Read the full answer
Mercury 2.5325 words
Here is a simple, actionable 1-month plan to kickstart your journey toward better health and longevity. This guide focuses on three foundational pillars: Nutrition, Movement, and Sleep. Week 1: Awareness & Small Wins Goal: Build habits without overwhelming yourself.
Read the full answer
Our Verdict
Mercury 2.5
Mercury 2.5
GPT-5 Nano
GPT-5 NanoRunner-up

Not enough votes to call it. On the specs, Mercury 2.5 has the edge: bigger model tier, newer, bigger context window.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-5 Nano
Input
—
Output
—
Mercury 2.5
Input
$0.04
Output
$0.15
Where to run it

3 hosts

GPT-5 Nano2 hosts
HostInOutContextUptime
Azure AI Foundry$0.05 in·$0.40 out·400k·99.9% upOpenAI$0.05 in·$0.40 out·400k·100% up
Mercury 2.51 host
HostInOutContextUptime
Inception$0.04 in·$0.15 out·260k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 22 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

GPT-5 Nano is developed by OpenAI while Mercury 2.5 is developed by Inception. You can compare their actual outputs across 20 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5 Nano and Mercury 2.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 20 challenges so you can judge which fits your needs best.

This page shows a side-by-side comparison of GPT-5 Nano and Mercury 2.5 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 Nano logoDeepSeek V4 Flash Vision Exp logo
GPT-5 Nano vs DeepSeek V4 Flash Vision ExpLanded Sep 2026
Mercury 2.5 logoSolar Pro 4 logo
Mercury 2.5 vs Solar Pro 4Landed Sep 2026
GPT-5 Nano logoHy3 logo
GPT-5 Nano vs Hy3Landed Sep 2026
Mercury 2.5 logoQwen3.7 Flash logo
Mercury 2.5 vs Qwen3.7 FlashLanded Sep 2026
GPT-5 Nano logoLing 3.0 Flash logo
GPT-5 Nano vs Ling 3.0 FlashLanded Sep 2026
Mercury 2.5 logoMuse Glimmer 30B logo
Mercury 2.5 vs Muse Glimmer 30BLanded Sep 2026
GPT-5 Nano logoGLM 5.3 logo
GPT-5 Nano vs GLM 5.3Landed Sep 2026
Mercury 2.5 logoTernary Bonsai 2 27B logo
Mercury 2.5 vs Ternary Bonsai 2 27BLanded Sep 2026

Same lab, same size, long tail

GPT-5 Nano logoGPT-6 Astra Pro logo
GPT-5 Nano vs GPT-6 Astra ProSame lab
GPT-5 Nano logoGPT-6 Astra logo
GPT-5 Nano vs GPT-6 AstraSame lab
Mercury 2.5 logoMercury 2.5 Preview logo
Mercury 2.5 vs Mercury 2.5 PreviewSame lab
Mercury 2.5 logoMercury logo
Mercury 2.5 vs MercurySame lab
Mercury 2.5 logoOpenRouter Fusion · Quality (Jun 2026) logo
Mercury 2.5 vs OpenRouter Fusion · Quality (Jun 2026)New provider
Mercury 2.5 logoGemini 1.5 Pro logo
Mercury 2.5 vs Gemini 1.5 ProSame size
GPT-5 Nano logoGemini 2.5 Flash Lite Preview 06-17 logo
GPT-5 Nano vs Gemini 2.5 Flash Lite Preview 06-17Same size
Mercury 2.5 logoGemini 2.5 Flash Lite Preview 09-2025 logo
Mercury 2.5 vs Gemini 2.5 Flash Lite Preview 09-2025Same size

Model pages

GPT-5 Nano logo
GPT-5 Nano59 outputs, specs and price
Mercury 2.5 logo
Mercury 2.520 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