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  5. Gemini 2.5 Flash PreviewvsGPT-6 Luna
Updated Sep 2026

Gemini 2.5 Flash PreviewvsGPT-6 Luna

GPT-6 Luna is cheaper than Gemini 2.5 Flash Preview at $0.1/M vs $0.15/M input tokens.

Gemini 2.5 Flash Preview and GPT-6 Luna compared across 2 shared prompts
SpecGemini 2.5 Flash PreviewGPT-6 Luna
Input price$0.15/M tokens$0.1/M tokens
Output price$0.6/M tokens$0.5/M tokens
Context window1.0M tokens1.1M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedApr 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from every prompt 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…

Gemini 2.5 Flash Preview221 words
Dish Name: Sunshine Lemon-Ricotta Mugs (Sweet & Simple!) This light and flavorful dessert comes together quickly for a little sweet treat . Ingredients (7 Common Pantry Staples): Ricotta cheese (whole milk or part-skim) Granulated sugar Lemon zest (from one lemon) Vanilla extract All-purpose flour Baking powder Large…
Read the full answer
GPT-6 Luna113 words
Crispy Parmesan Chickpeas A crunchy, savory snack with a cheesy finish Ingredients (7): 1 can chickpeas, drained and dried 1 tablespoon olive oil ½ teaspoon salt ½ teaspoon paprika ¼ teaspoon garlic powder ¼ cup grated Parmesan 1 tablespoon lemon juice Prep time: 5 minutes Cook time: 30–35 minutes Instructions: Heat…
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…

Gemini 2.5 Flash Preview960 words
<s) with practical, beginner-friendly tips for each.\"\nHere\'s a simple, actionable 1-month plan for someone starting their journey towards better health and longev\nity, focusing on three key areas: Diet, Movement, and Sleep.\n\nThis plan is designed to be beginner-friendly and build sustainable habits.
Read the full answer
GPT-6 Luna330 words
A simple 1-month starter plan Choose three foundations: food, movement, and sleep. Aim for steady habits, not perfection. If you have a health condition, significant pain, or concerns about changing your activity or diet, check with a healthcare professional first.
Read the full answer
Our Verdict
GPT-6 Luna
GPT-6 Luna
Gemini 2.5 Flash Preview
Gemini 2.5 Flash PreviewRunner-up

Not enough votes to call it. On the specs, GPT-6 Luna has the edge: bigger model tier, newer.

Too close to call
API pricing

Cost per 1M tokens

Gemini 2.5 Flash Preview
Input
$0.15
Output
$0.60
GPT-6 Luna
Input
$0.10
1.5× cheaper
Output
$0.50
1.2× cheaper

GPT-6 Luna is cheaper on both: 1.5× input, 1.2× output.

Where to run it

3 hosts, cheapest first

Gemini 2.5 Flash Preview

No hosts listed on OpenRouter.

GPT-6 Luna3 hosts
HostInOutContextUptime
Azure AI Foundry$0.10 in·$0.50 out·1.1M·88.4% upOpenAI$0.10 in·$0.50 out·1.1M·99.9% upAmazon Bedrock$0.11 in·$0.55 out·1.1M·99.8% up

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

Research

What we learned reading every model

FAQ

Common questions

Gemini 2.5 Flash Preview is developed by Google AI while GPT-6 Luna is developed by OpenAI. Gemini 2.5 Flash Preview has a 1.0M token context window vs GPT-6 Luna's 1.1M. You can compare their actual outputs across 2 challenges on Rival to see how they differ in practice.

It depends on your use case. Gemini 2.5 Flash Preview and GPT-6 Luna 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.

Gemini 2.5 Flash Preview costs $0.15/M input tokens and GPT-6 Luna costs $0.1/M input tokens. GPT-6 Luna is $0.05/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 Gemini 2.5 Flash Preview and GPT-6 Luna 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

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Same lab, same size, long tail

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Gemini 2.5 Flash Preview vs Gemini 3.8 FlashSame lab
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GPT-6 Luna vs GPT-6 Luna ProSame lab
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Model pages

Gemini 2.5 Flash Preview logo
Gemini 2.5 Flash Preview28 outputs, specs and price
GPT-6 Luna logo
GPT-6 Luna20 outputs, specs and price
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