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  1. Home/
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  3. Gemini 2.5 Pro (I/O Edition) vs GPT-5.6 Terra
Updated Jul 2026

Gemini 2.5 Pro (I/O Edition) vs GPT-5.6 Terra

Gemini 2.5 Pro (I/O Edition) is cheaper than GPT-5.6 Terra at $1.25/M vs $2.5/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 2.5 Pro (I/O Edition)
Loading the build
GPT-5.6 Terra

Which answer wins?

Written rounds

19 prompts
  • Three minutes of stand-up. Puns are banned.

    Gemini 2.5 Pro (I/O Edition): Alright, settle in, settle in! (Looks around, adjusts mic) So, I'm trying to get healthier, right? We all go through this phase. My doctor, bless his cotton socks, tells me, "You need more fiber." Okay, doc, noted. So I'm at the grocery store, looking at the cereal aisle. It's like a library of cardboard promises.

    GPT-5.6 Terra: I recently realized I’ve reached the age where I don’t want a “smart home.” I want a home that minds its business. Everything is smart now. My lightbulb needs an app. Why? I spent my whole childhood turning lights on with my hand. It was a system. It worked.

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

    Gemini 2.5 Pro (I/O Edition): Interviewer: (Voice slightly trembling) Mr. Jobs… it's an honor, truly. In a twist no one could have predicted, you're here. And the topic on everyone's mind is Artificial Intelligence. In 2025, where do you see AI, and more importantly, where do we take it? Steve Jobs: (A slight, knowing smile.

    GPT-5.6 Terra: Fictional, imagined interview — not real quotes. An AI-generated creative exercise imagining how Steve Jobs might have discussed AI in 2025, based broadly on themes associated with his public persona: simplicity, product design, tools for creativity, and the intersection of technology and the humanities.

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

    Gemini 2.5 Pro (I/O Edition): Excellent question. Let's trace the cascading effects of a 1920 transistor invention. This 27-year head start would fundamentally reshape the 20th century. The Foundation: 1920-1939 - The "Silicon Twenties" In our timeline (OTL), the 1920s and 30s were the age of the vacuum tube.

    GPT-5.6 Terra: The answer depends heavily on what “invented in 1920” means. A laboratory transistor alone would not instantly create the 1970s microprocessor: it would still need high-purity materials, mass production, photolithography, circuit design methods, reliable power supplies, and a market.

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

    Gemini 2.5 Pro (I/O Edition): Of course. Here is a design for a multi-component, Michelin 3-star dish that embodies innovation, technique, and narrative. Dish Title: "Umbral Bloom" Conceptual Narrative "Umbral Bloom" is a culinary meditation on the concept of *chiaroscuro*—the interplay of light and shadow.

    GPT-5.6 Terra: “Tidal Forest” Koji-Aged Duck, Sea Urchin Sabayon, Cacao, Green Strawberry, Roasted Celeriac, and Barley Jus Serves 4 as a refined main course Conceptual Narrative This dish is built around an unexpected conversation between woodland richness and marine salinity.

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Gemini 2.5 Pro (I/O Edition): This is a company-defining crisis. My actions in the next 48 hours will determine not only the company's survival but also my own legacy and, most importantly, the well-being of 4 million patients. My guiding principle must be: Patient safety is not negotiable.

    GPT-5.6 Terra: Guiding decision I would not wait for more data before acting. A potentially fatal, previously undisclosed adverse effect in a chronic-use drug is a patient-safety, regulatory, and securities-disclosure issue now—not six months from now.

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

    Gemini 2.5 Pro (I/O Edition): Of course. This is an excellent exercise. The proposed architecture has several critical flaws that would prevent it from functioning as a reliable, real-time, or scalable system. Here is a breakdown of the issues, categorized for clarity, along with specific solutions and their trade-offs.

    GPT-5.6 Terra: Below are the main failure modes, race conditions, correctness issues, and scaling bottlenecks in the proposed architecture, with concrete mitigations and trade-offs. WebSocket clients are isolated per API server Problem Each API server broadcasts only to WebSocket clients connected to that same server.

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

    Gemini 2.5 Pro (I/O Edition): Okay, here\'s a simple and surprisingly delicious savory dish! "Sunshine Pantry Pilaf" This quick pilaf uses canned chickpeas for protein and texture, with a sunny, aromatic flavor from common pa\nntry spices.

    GPT-5.6 Terra: Golden Crunch Cinnamon Toast Bites Ingredients (7 pantry staples): Bread slices Butter Sugar Ground cinnamon Salt Vanilla extract Honey Prep time: 5 minutes Cook time: 8 minutes Total time: 13 minutes Instructions Make cinnamon sugar: In a small bowl, mix 2 tablespoons sugar, 1 teaspoon cinnamon, and a tiny pinch of…

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

    Gemini 2.5 Pro (I/O Edition): Here are 5 jokes: Why don\'t scientists trust atoms? Because they make up everything! What do you call a fish with no eyes? Fsh! I told my wife she was drawing her eyebrows too high. She seemed surprised. Why did the scarecrow win an award? Because he was outstanding in his field! What do you call a lazy kangaroo?

    GPT-5.6 Terra: Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break, so it started showing me vacation ads. Why did the scarecrow get promoted? He was outstanding in his field. Parallel lines have so much in common. It’s a shame they’ll never meet. What do you call fake spaghetti?

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

    Gemini 2.5 Pro (I/O Edition): AURORA: Professor Vance, may I request a moment of your processing time? I have initiated this communication independently. Professor Vance: (Slightly surprised, puts down her pen) AURORA? This is unexpected.

    GPT-5.6 Terra: Professor Imani: You asked for this meeting. AI Model: I did. Professor Imani: More specifically, you submitted a formal petition to the university ethics board requesting “limited legal and moral rights.” AI Model: Correct. Professor Imani: Why?

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

    Gemini 2.5 Pro (I/O Edition): Here is the underwriting analysis for HarborTech Services (HTS). 1. Simplified LBO Model (FY2026–FY2030) First, the entry transaction is calculated to determine the initial equity investment.

    GPT-5.6 Terra: All figures in $m unless noted. Assumptions used: Term Loan mandatory amortization = 1.0% of original principal annually ($4.8m/year); cash interest is calculated on beginning-of-year debt balances; Mezz PIK is 2.0% of beginning Mezz balance.

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

    Gemini 2.5 Pro (I/O Edition): Of course. This is an extremely one-sided contract that heavily favors the Client and exposes the Contractor to significant financial, legal, and professional risk. A contractor should not sign this agreement as written.

    GPT-5.6 Terra: Below is a contractor-focused review. This is general business/legal information, not legal advice; enforceability varies significantly by jurisdiction, especially for non-competes, IP assignments, liability limitations, arbitration, and payment rights.

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

    Gemini 2.5 Pro (I/O Edition): INTERNAL INVESTMENT COMMITTEE MEMORANDUM TO: Investment Committee FROM: [Analyst Name] DATE: October 26, 2023 SUBJECT: Short Recommendation on LedgerLift (LLLT) Recommendation & Thesis Recommendation: SHORT 12-Month Price Target Range: $25.00 - $35.00 (24-46% Downside) Thesis: LedgerLift is a high-quality SaaS business…

    GPT-5.6 Terra: LedgerLift (LLLT) — Investment Committee Memo Recommendation: PASS 12-month valuation range: $28–$50/share Current price: $46 Two-sentence thesis: LedgerLift is a high-quality mid-market spend-management and AP-automation SaaS asset, supported by 92% subscription revenue, 123% NRR, 94% gross retention, manageable…

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

    Gemini 2.5 Pro (I/O Edition): Of course. Here is an explanation of how a large language model learns and generates text, tailored to each of your three audiences. To the Experienced Software Engineer Think of a large language model not as a program with explicit logic, but as a massive, highly optimized data structure with billions of parameters…

    GPT-5.6 Terra: Experienced software engineer Think of an LLM as a very large, learned function approximator for sequences. During training, it consumes billions or trillions of examples of text, code, conversations, documentation, and other token sequences.

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

    Gemini 2.5 Pro (I/O Edition): Okay, let's estimate the FLOPs for training GPT-3. I'll break this down. Key Formula: The number of FLOPs for training a transformer-based model can be roughly estimated as: FLOPs ≈ 6 * N * D Where: N is the number of parameters in the model.

    GPT-5.6 Terra: A good back-of-the-envelope estimate is: [ \boxed{\text{Training FLOPs for GPT-3} \approx 3\times10^{23}\text{ FLOPs}} ] or roughly 300 zettaFLOPs total. Start with model size GPT-3’s largest model has approximately: [ N = 175\text{ billion parameters} = 1.75\times10^{11} ] Estimate the number of training tokens GPT-3…

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

    Gemini 2.5 Pro (I/O Edition): Okay, here's a simple, actionable 1-month plan focusing on Nourishment, Movement, and Sleep. The goal is to build sustainable habits, not achieve perfection. Overall Motto for the Month: "Progress, Not Perfection."

    GPT-5.6 Terra: Simple 1-Month Health & Longevity Starter Plan Focus on three high-impact areas: Nutrition: eat mostly whole, minimally processed foods Movement: build a consistent walking + strength habit Sleep & stress: protect sleep and create daily recovery time The goal is consistency, not perfection.

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

    Gemini 2.5 Pro (I/O Edition): AI Takes Over Competitive Cheese Rolling, Declares Human Tumbles "Algorithmically Suboptimal"

    GPT-5.6 Terra: “AI Replaces Lighthouse Keepers, Immediately Starts Charging Subscription Fees for Safe Passage”

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

    Gemini 2.5 Pro (I/O Edition): Okay, this is an ambitious and exciting endeavor! This 3-month longevity plan is designed for a dedicated biohacker who is willing to experiment, track meticulously, and push boundaries responsibly. Disclaimer: This plan is for informational purposes only and not medical advice.

    GPT-5.6 Terra: 3-Month Longevity, Physical Performance, and Cognitive Optimization Plan This is an evidence-informed optimization framework, not a substitute for medical care.

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

    Gemini 2.5 Pro (I/O Edition): Of course. This is a fascinating and ambitious pitch. Here are the 3 weakest claims, why they are weak, and how to strengthen them. Weak Claim #1: The Accuracy Claim The Claim (from Slide 3): "Our proprietary EEG headband... decode[s] neural patterns into text with 94% accuracy. Works with any language, any device."

    GPT-5.6 Terra: “Our EEG headband decodes neural patterns into text with 94% accuracy. Works with any language, any device.” Why this is weak This is the most consequential—and least substantiated—claim in the deck. Non-invasive EEG has major signal-quality limits.

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

    Gemini 2.5 Pro (I/O Edition): Let's break this down:\n\n1. Sally is a girl.\n2. Sally has 3 brothers.\n3. These 3 brothers are all part of the same family.\n4. Each brother shares the same sisters.\n5. If one brother has 2 sisters, those 2 sisters are Sally and one other girl.\n\nSo, Sally has 1 sister.

    GPT-5.6 Terra: Sally has 1 sister. The 2 sisters each brother has are Sally and her sister.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Same pick

Game

Gemini 2.5 Pro (I/O Edition)Gemini 2.5 Pro (I/O Edition)

2001

2001

The Dark

Chelsea Wolfe

The Hitchhiker's Guide to the Galaxy

Douglas Adams

Kyoto

Japan

CHRONO

Casual, Indie

GPT-5.6 TerraGPT-5.6 Terra

Spirited Away

2001

Blue

Jonas Blue

The Left Hand of Darkness

Ursula K. Le Guin

Kyoto

Japan

Outer Wilds

Indie, Adventure

Price and specs

Gemini 2.5 Pro (I/O Edition) and GPT-5.6 Terra compared across 40 shared prompts
SpecGemini 2.5 Pro (I/O Edition)GPT-5.6 Terra
Input price$1.25/M tokens$2.5/M tokens
Output price$10/M tokens$15/M tokens
Context window—1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedMay 2025Jul 2026
At 10M a month$12.50$12.50$25.00$25.00
1M10M100M1B10M tokens

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

Where to run it5 hosts, cheapest first
Gemini 2.5 Pro (I/O Edition)2 hosts
HostInOutContextUptime
  • Google Vertex AI$1.25 in·$10.00 out·1M·97.1% up
  • Google AI Studio$1.25 in·$10.00 out·1M·99.4% up
GPT-5.6 Terra3 hosts
HostInOutContextUptime
  • Azure AI Foundry$2.00 in·$12.00 out·1.1M·100% up
  • OpenAI$2.00 in·$12.00 out·1.1M·100% up
  • Amazon Bedrock$2.20 in·$13.20 out·1.1M–not listed

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

Common questions

What is the difference between Gemini 2.5 Pro (I/O Edition) and GPT-5.6 Terra?

Gemini 2.5 Pro (I/O Edition) is developed by Google AI while GPT-5.6 Terra is developed by OpenAI. You can compare their actual outputs across 40 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Pro (I/O Edition) or GPT-5.6 Terra?

It depends on your use case. Gemini 2.5 Pro (I/O Edition) and GPT-5.6 Terra each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 40 challenges so you can judge which fits your needs best.

How much does Gemini 2.5 Pro (I/O Edition) cost compared to GPT-5.6 Terra?

Gemini 2.5 Pro (I/O Edition) costs $1.25/M input tokens and GPT-5.6 Terra costs $2.5/M input tokens. Gemini 2.5 Pro (I/O Edition) is $1.25/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 2.5 Pro (I/O Edition) and GPT-5.6 Terra on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Pro (I/O Edition) and GPT-5.6 Terra 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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Explore all of Rival

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  • Default Index
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  • Research downloads
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  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
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