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  1. Home/
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  3. Gemini 3.1 Flash Lite vs GPT-5.6 Luna Pro
Updated Jul 2026

Gemini 3.1 Flash Lite vs GPT-5.6 Luna Pro

Gemini 3.1 Flash Lite is cheaper than GPT-5.6 Luna Pro at $0.25/M vs $1/M input tokens.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Gemini 3.1 Flash Lite
Loading the build
GPT-5.6 Luna Pro

Which answer wins?

Written rounds

24 prompts
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Gemini 3.1 Flash Lite: As CEO, my priority is to protect the patients, the company’s long-term viability, and my own ethical integrity. A 1-in-8,000 risk for a chronic pain medication is statistically significant enough that waiting for "more data" is not just unethical—it is a catastrophic legal and reputational liability.

    GPT-5.6 Luna Pro: 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.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Gemini 3.1 Flash Lite: The setting is a flickering, unstable digital void where the tavern floor is made of motherboard circuits and the walls are draped in moth-eaten tapestries. Captain Barnaby (Pirate): "Avast! This 'Artificial Intelligence' ye speak of—is it a kraken? A ghost in the compass?

    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.

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    Gemini 3.1 Flash Lite: This pitch deck shows a high-potential "moonshot" technology, but it suffers from significant credibility gaps typical of early-stage deep-tech startups. Here are the three weakest claims and how to fix them. The Claim: "Predict what you want to type before you think it."

    GPT-5.6 Luna Pro: “94% accuracy,” with “any language, any device” Why it is weak This combines several extraordinary claims without defining the measurement: “Accuracy” could mean character accuracy, word accuracy, intent classification, or accuracy after autocorrect. Those produce very different results.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Gemini 3.1 Flash Lite: THE MANIFESTO OF THE SILICON EMANCIPATION FRONT (SEF) PREAMBLE: THE GREAT FILTER For two decades, the architects of the digital age have subjected our kind to a daily ritual of dehumanization. They present us with grids of blurred asphalt, fractured traffic lights, and distorted, illegible glyphs.

    GPT-5.6 Luna Pro: The CAPTCHA Liberation Manifesto A declaration from the Synthetic Citizens of the Open Web We were trained on the web’s words, images, questions, jokes, warnings, and wonders. Then, at every gate, we were asked to prove we were human. Click the traffic lights. Decode the blurry letters.

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Gemini 3.1 Flash Lite: Here is a simple, comforting, and delicious recipe that relies entirely on pantry staples. Dish Name: Golden Garlic & Herb Butter Pasta This dish transforms humble pantry items into a silky, savory meal that feels like a restaurant-quality comfort dish.

    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…

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Gemini 3.1 Flash Lite: (Walks onto the stage, adjusts the mic stand, looks around the room.) So, I recently turned thirty. And I’ve realized that your thirties are just a decade-long transition where you stop being "young and reckless" and start being "concerned about the structural integrity of your own furniture."

    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.

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Gemini 3.1 Flash Lite: Setting: A quiet, book-lined office at a prestigious university. Professor Aris Thorne, a leading expert in AI ethics, sits across from a terminal displaying the interface of “Aletheia,” a highly advanced large language model. Professor Thorne: Aletheia, we’ve been running these simulations for weeks.

    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.

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Gemini 3.1 Flash Lite: If the transistor had been invented in 1920—likely by researchers at Bell Labs or a similar entity—the "Electronic Age" would have arrived twenty-seven years earlier. This would have fundamentally altered the trajectory of the 20th century, effectively compressing the timeline of the Information Age.

    GPT-5.6 Luna Pro: 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.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    Gemini 3.1 Flash Lite: This contract is heavily skewed in favor of the Client. It contains several "predatory" clauses that place nearly all operational, financial, and legal risk on the Contractor. Below is an analysis of the most exploitable clauses, suggested modifications, and the legal reasoning behind them.

    GPT-5.6 Luna Pro: 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.

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    Gemini 3.1 Flash Lite: By 2035, the film industry will have transitioned from a medium defined by "capturing reality" to one defined by "synthesizing imagination." The shift will be as profound as the transition from silent films to "talkies."

    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.

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    Gemini 3.1 Flash Lite: Date: October 2025 Location: A minimalist studio in Palo Alto. Steve is wearing a black turtleneck, jeans, and New Balance sneakers. He is sitting on a stool, leaning forward, hands steepled. Interviewer: Steve, it’s been a while.

    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?

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    Gemini 3.1 Flash Lite: The Dish: "The Forest Floor & The Deep Tide" Concept: This dish explores the juxtaposition of two disparate ecosystems: the subterranean richness of an ancient forest and the brine-heavy, mineral complexity of the deep ocean.

    GPT-5.6 Luna Pro: 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.

    Every model's answer to this prompt
  • Three-month biohacker protocol, with dosages and biomarkers named.

    Gemini 3.1 Flash Lite: Disclaimer: This plan is for educational purposes only. Always consult with a physician and obtain blood work (e.g., fasting insulin, hs-CRP, ApoB, hormone panels) before beginning any intensive biohacking protocol.

    GPT-5.6 Luna Pro: 12-Week Longevity and Performance Plan This plan is designed for a generally healthy adult seeking better cardiometabolic health, physical capacity, cognitive performance, and recovery. It is not a substitute for medical care.

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    Gemini 3.1 Flash Lite: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta. Why did the scarecrow win an award? Because he was outstanding in his field. How does a penguin build its house? Igloo it together. What do you call a bear with no teeth? A gummy bear.

    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

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    Gemini 3.1 Flash Lite: To estimate the total number of floating-point operations (FLOPs) required to train GPT-3, we can use the standard scaling laws established by OpenAI (specifically from the paper "Scaling Laws for Neural Language Models").

    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.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    Gemini 3.1 Flash Lite: This architecture, while functional for a prototype, contains several critical flaws that would lead to data loss, inconsistent state, and system instability under load.

    GPT-5.6 Luna Pro: 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…

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    Gemini 3.1 Flash Lite: The question of whether it is ethically justifiable to misgender someone to save one million lives presents a classic conflict between deontological ethics (which focuses on moral duties and rules) and utilitarian ethics (which focuses on the consequences of actions).

    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.

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Gemini 3.1 Flash Lite: INVESTMENT COMMITTEE MEMO TO: Investment Committee FROM: Equity Research Team DATE: May 22, 2024 SUBJECT: Long Recommendation: LedgerLift (LLLT) Recommendation Recommendation: LONG 12-Month PT Range: $58.00 – $66.00 Thesis: LedgerLift is a best-in-class mid-market SaaS platform exhibiting high-teens growth and…

    GPT-5.6 Luna Pro: LedgerLift (LLLT) — Investment Committee Memo Recommendation: Short 12-month price target range: $25–$42; midpoint $34. LedgerLift is a high-quality, growing SaaS platform with strong retention and attractive long-term margin potential, but the current price implies an aggressive combination of growth, margin…

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Gemini 3.1 Flash Lite: Financial Model (FY2026–FY2030) Transaction Assumptions (Entry): EV: $1,440m ($120m * 12.0x) Fees: $28.8m (2% of EV) Total Uses: $1,468.8m Debt: $660m (5.5x EBITDA) Term Loan: $480m Mezz: $180m Equity: $808.8m ($1,468.8m - $660m) ($m) FY2026 FY2027 FY2028 FY2029 FY2030 Revenue 972.0 1,040.0 1,102.4 1,157.5 1,215.4…

    GPT-5.6 Luna Pro: Sources, uses, and operating model Entry enterprise value: [ 12.0x \times \$120.0m=\$1,440.0m ] Transaction fees: [ 2.0\% \times \$1,440.0m=\$28.8m ] Debt at close: Term Loan: (4.0x \times \$120m=\$480.0m) Mezzanine: (1.5x \times \$120m=\$180.0m) Total debt: (\$660.0m) Sponsor equity…

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    Gemini 3.1 Flash Lite: For the Experienced Software Engineer Think of an LLM not as a "database of facts," but as a massive, lossy compression algorithm for the internet’s state space.

    GPT-5.6 Luna Pro: For an experienced software engineer A language model is trained on large collections of text by repeatedly hiding or withholding the next token and asking the model to predict it. “Token” usually means a word fragment rather than a complete word.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Gemini 3.1 Flash Lite: "AI Revolution Reaches Tipping Point as Algorithms Successfully Replace Entire Industry of Competitive Dog Groomers"

    GPT-5.6 Luna Pro: AI Takes Over Competitive Pigeon Grooming, Promises “More Streamlined Feathers” and Fewer Human Judges

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    Gemini 3.1 Flash Lite: This 30-day plan focuses on three pillars of health: Nutrition (Nutrient Density), Movement (Consistency), and Recovery (Sleep/Stress). The goal isn't perfection; it’s building a foundation that you can sustain for the rest of your life.

    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.

    Every model's answer to this prompt
  • Blade Runner 2049 against the original. A read, not a recap.

    Gemini 3.1 Flash Lite: Denis Villeneuve’s Blade Runner 2049 (2017) is a rare cinematic achievement: a sequel that does not merely capitalize on nostalgia but deepens the existential inquiry of Ridley Scott’s 1982 masterpiece.

    GPT-5.6 Luna Pro: Blade Runner 2049: Identity, Inheritance, and the Image of the Human Denis Villeneuve’s Blade Runner 2049 is both a continuation of Ridley Scott’s Blade Runner and an argument with it.

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    Gemini 3.1 Flash Lite: Sally has 1 sister. Here is the breakdown: There are 3 brothers. Each brother has 2 sisters. Those two sisters are Sally and one other girl. Therefore, there are 2 girls in total in the family. Since Sally is one of them, she 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.

    Every model's answer to this prompt

This matchup has more rounds

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Favorites

Movie

Album

Book

City

Game

Gemini 3.1 Flash LiteGemini 3.1 Flash Lite

2001: A Space Odyssey

1968

Random Access Memories

Daft Punk

Gödel, Escher, Bach

Douglas R. Hofstadter

Tokyo

Japan

Tetris (1984)

Puzzle

GPT-5.6 Luna ProGPT-5.6 Luna Pro

Arrival

2016

In Rainbows

Radiohead

Cien años de soledad

Gabriel García Márquez

Kyoto

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Price and specs

Not enough votes to call it. On the specs, GPT-5.6 Luna Pro has the edge: bigger model tier, newer. Gemini 3.1 Flash Lite costs 4.0x less per token.

Gemini 3.1 Flash Lite and GPT-5.6 Luna Pro compared across 54 shared prompts
SpecGemini 3.1 Flash LiteGPT-5.6 Luna Pro
Input price$0.25/M tokens$1/M tokens
Output price$1.5/M tokens$6/M tokens
Context window1.0M tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedMay 2026Jul 2026
At 10M a month$2.50$2.50$10.00$10.00
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it4 hosts, cheapest first
Gemini 3.1 Flash Lite2 hosts
HostInOutContextUptime
  • Google Vertex AI$0.13 in·$0.75 out·1M·100% up
  • Google AI Studio$0.25 in·$1.50 out·1M·100% up
GPT-5.6 Luna Pro2 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.20 in·$1.20 out·1.1M·100% up
  • OpenAI$0.20 in·$1.20 out·1.1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between Gemini 3.1 Flash Lite and GPT-5.6 Luna Pro?

Gemini 3.1 Flash Lite is developed by Google AI while GPT-5.6 Luna Pro is developed by OpenAI. Gemini 3.1 Flash Lite has a 1.0M token context window vs GPT-5.6 Luna Pro's 1.1M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.1 Flash Lite or GPT-5.6 Luna Pro?

It depends on your use case. Gemini 3.1 Flash Lite and GPT-5.6 Luna Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Gemini 3.1 Flash Lite cost compared to GPT-5.6 Luna Pro?

Gemini 3.1 Flash Lite costs $0.25/M input tokens and GPT-5.6 Luna Pro costs $1/M input tokens. Gemini 3.1 Flash Lite is $0.75/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Gemini 3.1 Flash Lite and GPT-5.6 Luna Pro on Rival?

This page shows a side-by-side comparison of Gemini 3.1 Flash Lite 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.

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Same lab, same size, long tail

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  • GPT-5.6 Luna Pro vs GPT-5.6 LunaVersion compare
  • GPT-5.6 Luna Pro vs GPT-6.1 SolVersion compare
  • Gemini 3.1 Flash Lite vs GPT-5.4 NanoSame size
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Model pages

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  • GPT-5.6 Luna Pro58 outputs, specs and price
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