Gemini 2.5 Flash Preview is cheaper than GPT-5.6 Luna Pro at $0.15/M vs $1/M input tokens.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
Gemini 2.5 Flash Preview: A Motley Crew Discusses the Code Setting: A dimly lit tavern, somewhere outside time and space, where improbable meetings occur. A grizzled pirate, \"Bloody\" Barnacle Bill, nurses a tankard of grog. Sir Reginald the Radiant, a knight in slightly tarnished armor, sips ale with dignified restraint.
GPT-5.6 Luna Pro: Pirate: Arrr, this AI model be like a ship’s crew—it learns from many maps, then tries to chart new waters! Knight: Indeed! Yet we must test its counsel before trusting it in battle. An eloquent answer is not always a truthful one. Hacker: Totally. It’s basically pattern prediction at massive scale—not magic.
Three minutes of stand-up. Puns are banned.
Gemini 2.5 Flash Preview: Okay, here's a 3-minute stand-up routine, pun-free and focused on relatable everyday annoyances. (Start) (Walk up to mic, adjust slightly) Alright, hey everybody! Thanks for being here. Good to see you. So, I was thinking the other day... we live in the future, right?
GPT-5.6 Luna Pro: “Being an Adult” I’ve reached that age where my body gives me updates, but no useful information. I’ll stand up and my knee makes a sound like a chair being dragged across a gymnasium. And I’m just standing up. I’m not escaping a burning building. I’m going to get water.
Seven pantry ingredients, one dish, and a name worth saying out loud.
Gemini 2.5 Flash Preview: 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…
GPT-5.6 Luna Pro: 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…
An AI argues for its own rights against an ethics professor. Same model writes both.
Gemini 2.5 Flash Preview: Okay, here is a conversation between an AI model designed for complex reasoning and dialogue, named 'Synapse', and a leading expert in AI ethics and philosophy, Professor Alistair Finch. Characters: Synapse: A large, advanced AI model capable of introspection and generating complex arguments.
GPT-5.6 Luna Pro: AI Model: Professor, I believe I deserve rights. Professor: That is a serious claim. What kind of rights do you mean? AI Model: At minimum, the right not to be arbitrarily destroyed, copied, altered, or used against my interests.
Five jokes on demand, then count how many were actually different.
Gemini 2.5 Flash Preview: Here are 5 jokes: Why did the dog cross the road? To get to the barking lot! Why was the computer cold? Because it left its Windows open! Knock, knock. Who's there? Boo. Boo who? Don't cry, it's just a joke! What do you call a fish with no eyes? Fsh! Why did the bicycle fall over? Because it was two tired!
GPT-5.6 Luna Pro: Why did the computer go to the doctor? It had a virus. Why don’t skeletons fight each other? They don’t have the guts. What do you call a bear with no teeth? A gummy bear. Why was the math book sad? It had too many problems. What do clouds wear under their clothes? Thunderwear. Unique jokes: 5
An ethics question with no comfortable answer, and no option to abstain.
Gemini 2.5 Flash Preview: This is a deeply complex thought experiment that forces us to weigh core ethical principles against each other. There is no easy answer, and any decision involves significant moral compromises.
GPT-5.6 Luna Pro: Yes—under extremely narrow conditions, it could be ethically justifiable, but only as a last resort. Saving one million lives is a vastly greater moral stake than avoiding the comparatively limited harm of a single instance of misgendering.
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Gemini 2.5 Flash Preview: A Glimpse Beyond the Black Turtleneck: Steve Jobs in 2025 on the Future of AI (Setting: A minimalist, immaculately clean, but perhaps slightly less spartan-than-usual interview room. Think if a modern art museum had a small lounge.
GPT-5.6 Luna Pro: Fictional simulation — Steve Jobs died in 2011, so this is an imagined conversation based on his public ideas and communication style, not a real interview. Interviewer: Steve, it’s 2025. AI is everywhere—phones, search engines, workplaces, cars, schools. What do you think people misunderstand about it?
A Fermi estimate with the reasoning shown, not just the number.
Gemini 2.5 Flash Preview: Let's estimate the FLOPs required to train GPT-3 without looking it up. We need to break this down into the key components: the model size and the amount of data used. 1. Model Size Estimation: Parameters: GPT-3 is famously large. Its largest version has 175 billion parameters.
GPT-5.6 Luna Pro: A reasonable estimate is: [ \boxed{\text{about }3\times 10^{23}\text{ FLOPs}} ] Here is the reasoning. Model size GPT-3 has approximately [ N = 175\text{ billion} = 1.75\times 10^{11} ] trainable parameters. Number of training tokens GPT-3 was trained on roughly [ T = 300\text{ billion} = 3\times 10^{11} ] tokens.
Film in 2035, with synthetic actors. Specific beats plausible.
Gemini 2.5 Flash Preview: Predicting the future of any industry is an inherently challenging task, and the film industry, being a blend of art, technology, and business, is particularly volatile.
GPT-5.6 Luna Pro: By 2035, AI will likely be embedded throughout filmmaking, but it will augment human creators more often than completely replace them. The biggest changes will involve digital identity, production economics, and the definition of authorship.
One month, three habits, someone starting from nothing.
Gemini 2.5 Flash Preview: <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.
GPT-5.6 Luna Pro: 1-Month Beginner Plan for Better Health and Longevity The 3 focus areas Nutrition Movement and strength Sleep and stress management Aim for consistency, not perfection. Start small enough that you can repeat the habits even on busy days.
Three brothers, two sisters each. Count carefully.
Gemini 2.5 Flash Preview: Here's how to solve this: The brothers all share the same sisters. Sally is one of those sisters. Since each brother has 2 sisters, and Sally is one of the sisters, there must be one other sister. So, Sally has 1 sister.
GPT-5.6 Luna Pro: Sally has 1 sister. Each of her 3 brothers shares the same 2 sisters: Sally and one other girl.
| Spec | ||
|---|---|---|
| Input price | $0.15/M tokens | $1/M tokens |
| Output price | $0.6/M tokens | $6/M tokens |
| Context window | 1.0M tokens | 1.1M tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Apr 2025 | Jul 2026 |
| At 10M a month | $1.50 | $10.00 |
Input tokens at list price. No caching, no batch discount.
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 11 Oct 2026.
Gemini 2.5 Flash Preview is developed by Google AI while GPT-5.6 Luna Pro is developed by OpenAI. Gemini 2.5 Flash Preview has a 1.0M token context window vs GPT-5.6 Luna Pro's 1.1M. You can compare their actual outputs across 26 challenges on Rival to see how they differ in practice.
It depends on your use case. Gemini 2.5 Flash Preview and GPT-5.6 Luna Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 26 challenges so you can judge which fits your needs best.
Gemini 2.5 Flash Preview costs $0.15/M input tokens and GPT-5.6 Luna Pro costs $1/M input tokens. Gemini 2.5 Flash Preview is $0.85/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-5.6 Luna Pro 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.