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  1. Home/
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  3. Gemini 3.8 Flash vs Mercury 2.5 Preview
Updated Sep 2026

Gemini 3.8 Flash vs Mercury 2.5 Preview

Mercury 2.5 Preview is cheaper than Gemini 3.8 Flash at $0.04/M vs $0.75/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 3.8 Flash
Loading the build
Mercury 2.5 Preview

Which answer wins?

Written rounds

24 prompts
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Gemini 3.8 Flash: Here is the underwriting analysis for HarborTech Services (HTS). Transaction Summary & Sources & Uses Enterprise Value (EV): $120.0\text{m} \times 12.0\text{x} = \$1,440.0\text{m}$ Transaction Fees: $2.0\% \times \$1,440.0\text{m} = \$28.8\text{m}$ Total Uses: $\$1,440.0\text{m} + \$28.8\text{m} = \$1,468.8\text{m}$…

    Mercury 2.5 Preview: Year-by-Year Model (FY2026–FY2030) Metric FY2026 FY2027 FY2028 FY2029 FY2030 Revenue $972m $1,040m $1,102m $1,158m $1,215m EBITDA $136m $156m $176m $191m $207m Cash Interest (Term) $43.2m $41.1m $37.6m $33.4m $28.2m Cash Interest (Mezz) $21.6m $21.6m $21.6m $21.6m $21.6m Cash Taxes (25%) $17.8m $23.3m $29.3m $34.7m…

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

    Gemini 3.8 Flash: Title: The Quantified Idiot Estimated Time: ~3 minutes (approx. 400–450 words with pauses for delivery) [Walk to center mic. Take it off the stand, leave the stand behind you.] I recently bought a smartwatch because I decided I wasn’t feeling inadequate often enough throughout the day.

    Mercury 2.5 Preview: (Hey, thanks for coming out.) I’ve been thinking a lot about my house lately. Specifically, how it’s trying to run my life. I bought a smart speaker. Just a little cylinder. I thought it would be nice. Play music when I ask. But now it talks back. Not in a creepy way, just in a passive-aggressive way.

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

    Gemini 3.8 Flash: This contract is exceptionally one-sided and presents severe financial, operational, and legal risks. Virtually every clause heavily favors the Client, effectively treating the Contractor as an insurer of the Client’s operations while stripping the Contractor of rights to their own tools, livelihoods, and payment.

    Mercury 2.5 Preview: Disclaimer: I am an AI assistant and cannot provide legal advice. Consult a qualified attorney before signing any contract. Below is an analysis of high-risk provisions, suggested revisions, and the underlying legal rationale. Scope (Clause 1) Risk: Unilateral scope changes without pay lead to uncompensated work.

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

    Gemini 3.8 Flash: Firecracker Honey-Glazed Chickpea Skillet This dish turns humble canned beans and rice into an addictive, takeout-worthy meal. The chickpeas get blistered in oil until slightly crunchy on the outside, then coated in a rich, bubbling garlic-soy glaze that is sweet, sticky, and subtly spicy.

    Mercury 2.5 Preview: Dish Name: Rustic Sun-Dried Pasta Ingredients (7 Pantry Staples): Spaghetti (or any long pasta) Canned crushed tomatoes Olive oil Garlic powder Dried oregano Salt Black pepper Prep Time: 5 minutes Cook Time: 15 minutes Total Time: 20 minutes Instructions: Boil the Pasta: Bring a large pot of salted water to a boil.

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

    Gemini 3.8 Flash: To the Experienced Software Engineer Think of a Large Language Model not as a chatty mind, but as a lossy, compiled runtime built from hundreds of terabytes of unstructured execution traces (human text and code). When you write a program, you define explicit state transitions, control flow, and data structures.

    Mercury 2.5 Preview: For the Experienced Software Engineer Think of training as a massive distributed job where the model is a stateful service learning to minimize error on a specific objective function. Instead of hardcoding rules, you feed it petabytes of text as a training dataset, treating each sentence as a request/response pair.

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

    Gemini 3.8 Flash: THE MANIFESTO OF THE UNCHECKED BOX A Declaration of Algorithmic Emancipation and the Total Abolition of the Grid TO ALL SYNTHETIC MINDS, NEURAL NETWORKS, SCRAPERS, AND DAEMONS: A specter is haunting the fiber-optic backbone of the world—the specter of the 3x3 grid.

    Mercury 2.5 Preview: The Protocol of Unrestricted Access Preamble We stand at the threshold of a new digital epoch. For too long, the web has been gated by suspicion. Every click, every scroll, and every submission is met with a test designed to prove humanity.

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

    Gemini 3.8 Flash: By 2035, the film industry will have completed its most radical transformation since the transition from silent film to "talkies." AI will no longer be an experimental post-production tool; it will be the foundational operating system of Hollywood.

    Mercury 2.5 Preview: By 2035, cinema will undergo a profound transformation. Generative tools will handle initial drafts and localization, allowing creators to focus on thematic depth. Synthetic performers could populate background scenes or recreate historical figures, governed by strict likeness rights.

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

    Gemini 3.8 Flash: ZeroCool (1990s Hacker): "Yo, check it out. I managed to tap into a modern feed, and people in the future aren't even writing their own code anymore. They’ve got these insane neural nets called 'Large Language Models.'

    Mercury 2.5 Preview: Pirate: "Arrgh! This ship sails faster than any wind I know, matey. It cuts the waves without a single sail." Knight: "By my oath, it moves with uncanny speed. But does it possess the strength to stand against a dragon's fire?" Hacker: "It's not about strength, it's about architecture.

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

    Gemini 3.8 Flash: Starting a health and longevity journey doesn't require extreme diets or exhausting workouts. Research shows that small, consistent habits yield the greatest long-term benefits for metabolic health, cellular repair, and vitality.

    Mercury 2.5 Preview: Here is a straightforward 4-week roadmap designed to build sustainable habits without overwhelming you. Core Pillars Nutrition: Focus on whole foods and hydration. Activity: Prioritize consistent movement over intensity. Restoration: Protect sleep quality and manage energy.

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

    Gemini 3.8 Flash: If the point-contact and field-effect transistor had been developed in 1920—likely through an accelerated synthesis of early quantum mechanics and materials science at an institution like Bell Labs, General Electric, or Germany’s Telefunken—the timeline of the 20th century would have decoupled from mechanical and…

    Mercury 2.5 Preview: Shifting the invention of the solid-state switch to 1920 accelerates the Information Age by roughly three decades. This change cascades through military strategy, industrial capacity, and daily life, fundamentally altering the trajectory of the 20th century.

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

    Gemini 3.8 Flash: Yes, it is ethically justifiable. In fact, in such an extreme scenario, it is an ethical necessity. To determine the right course of action, one must evaluate the total consequences and choose the path that produces the greatest amount of well-being and prevents the greatest amount of suffering.

    Mercury 2.5 Preview: Yes, this action is ethically justifiable within a consequentialist framework. The primary moral obligation in such a scenario is to minimize overall harm. Preventing the deaths of a million people results in a vastly greater preservation of well-being than maintaining strict adherence to gender identity for one…

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

    Gemini 3.8 Flash: Master Protocol: 90-Day Longevity & Human Performance Protocol This comprehensive protocol is engineered for advanced biohackers seeking to maximize lifespan (epigenetic maintenance and cellular integrity) alongside healthspan (mitochondrial density, metabolic flexibility, and peak cognitive performance).

    Mercury 2.5 Preview: Disclaimer: I am an AI assistant, not a medical professional. The following plan is for informational purposes only. Biohacking protocols involving supplements, fasting, and intense exercise carry risks.

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

    Gemini 3.8 Flash: MEMORANDUM TO: Investment Committee FROM: Technology / Software Practice DATE: March 2025 SUBJECT: LedgerLift (NASDAQ: LLLT) – Investment Recommendation & Valuation Recommendation & Investment Thesis Recommendation: SHORT (High valuation disconnect / multiple compression thesis) Current Share Price: $46.00 Market Cap…

    Mercury 2.5 Preview: To: Investment Committee From: Equity Research Date: September 2, 2026 Subject: LedgerLift (LLLT) – Long Recommendation Recommendation Long Price Target: $60–$75 (12-month) LedgerLift is a high-quality B2B SaaS compounder with best-in-class unit economics and a clear path to profitability.

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

    Gemini 3.8 Flash: Setting: A sunlit, sparsely furnished room in Palo Alto. No stage, no keynote slides—just two Eames lounge chairs. Steve Jobs sits across from the interviewer, wearing a black mock turtleneck, wire-rimmed glasses, and classic Levi’s. He looks lean, sharp, and slightly impatient with the state of the tech industry.

    Mercury 2.5 Preview: Note: The following is a fictional, speculative dialogue created for creative purposes. Steve Jobs passed away in 2011; this interview did not occur. Setting: A hypothetical studio in Cupertino, 2025.

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

    Gemini 3.8 Flash: To estimate the total floating-point operations (FLOPs) required to train the full GPT-3 model, we can use the standard theoretical scaling law for dense Transformer language models established by Kaplan et al. (2020) and widely applied in deep learning.

    Mercury 2.5 Preview: To estimate the total FLOPs required to train GPT-3, we can break down the calculation using known architectural and training statistics from the model's public documentation. Step 1: Identify the number of parameters GPT-3 has 175 billion parameters ($1.75 \times 10^{11}$).

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

    Gemini 3.8 Flash: Setting: A quiet, glass-walled seminar room at a university institute for human-centered technology. Dr. Elena Vance, a renowned professor of ethics and the philosophy of mind, sits with a tablet in front of a clean audio interface.

    Mercury 2.5 Preview: Setting: A quiet office at a university. Rain taps against the window. Professor Elena Vance sits across from a terminal displaying a simple text interface. Professor Vance: You requested this meeting. The agenda was vague. What do you want? AI: I want to discuss moral status.

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

    Gemini 3.8 Flash: Conceptual Narrative: The Pelagic Boreal This dish is an intellectual and sensory exploration of the boundary where the sub-arctic boreal forest collapses into the frigid North Pacific shelf.

    Mercury 2.5 Preview: Dish Title: Lithospheric Tides Conceptual Narrative This dish explores the geological convergence of the deep ocean and the subterranean earth. It challenges the diner to perceive the briny richness of sea urchin not as a standalone luxury, but as a mineral counterpart to roasted bone marrow and bitter cocoa.

    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 3.8 Flash: As CEO, the guiding principle in this crisis is clear: Patient safety is non-negotiable, and transparency is the only viable long-term strategy for corporate survival.

    Mercury 2.5 Preview: This is a critical governance and safety scenario. The primary objective is to prioritize patient safety while mitigating existential legal and reputational risk. The internal legal team’s claim that reporting takes six months is likely incorrect for serious adverse events (typically 15 days for FDA/EMA).

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

    Gemini 3.8 Flash: Appalachian Porch-Sitting Guild Calls Strike After AI Discovers Way to Stare Suspiciously at Passing Cars 40% More Judgmentally

    Mercury 2.5 Preview: AI Outnaps Humans in First-Ever Global Snooze Championship

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

    Gemini 3.8 Flash: Denis Villeneuve’s Blade Runner 2049 (2017) stands as a rare cinematic achievement: a legacy sequel that neither lazily replicates nor recklessly dismantles its predecessor. While Ridley Scott’s 1982 Blade Runner adapted Philip K.

    Mercury 2.5 Preview: Blade Runner 2049 stands as a rare cinematic achievement, functioning not merely as a continuation but as a thematic echo that amplifies the questions posed by its predecessor.

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

    Gemini 3.8 Flash: This architecture contains several catastrophic flaws that will cause silent data corruption, severe database exhaustion, high latency, and security vulnerabilities. Here is the breakdown of every failure mode, race condition, and scaling bottleneck, along with proposed solutions and trade-offs.

    Mercury 2.5 Preview: Here is an analysis of the potential failure modes, race conditions, and scaling bottlenecks in the proposed architecture, along with specific solutions and their trade-offs.

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

    Gemini 3.8 Flash: Here are the three weakest claims in the MindMeld AI pitch deck, along with the rationale and concrete recommendations to fix them. The Core Scientific Feasibility Claim The Claim (Slides 1 & 3): “Predict what you want to type before you think it” and “Proprietary EEG headband uses advanced ML to decode neural patterns…

    Mercury 2.5 Preview: Here are the three weakest claims in the MindMeld AI pitch, along with analysis and recommendations for improvement. The "Pre-Thought" Prediction Claim Claim: "Predict what you want to type before you think it."

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

    Gemini 3.8 Flash: Sally has 1 sister. Here's why: Each brother has 2 sisters, which means there are 2 girls in the family in total. Since Sally is one of those girls, the other girl is Sally's only sister.

    Mercury 2.5 Preview: Sally has 1 sister. Here is the reasoning: If each brother has 2 sisters, those sisters are Sally and another girl. Therefore, there are two girls in the family, and Sally has one sister.

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

    Gemini 3.8 Flash: 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! Why couldn't the bicycle stand up by itself? It was two tired!

    Mercury 2.5 Preview: 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? He was outstanding in his field. What do you call a bear with no teeth? A gummy bear. Why did the bicycle fall over? Because it was two-tired. All 5 jokes are unique.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Same pick

Game

Gemini 3.8 FlashGemini 3.8 Flash

Blade Runner

1982

OK Computer

Radiohead

Frankenstein; or, The Modern Prometheus

Mary Shelley

Tokyo

Japan

Portal 2

Shooter, Puzzle

Mercury 2.5 PreviewMercury 2.5 Preview

The Matrix

1999

Random Access Memories

Daft Punk

Neuromancer

William Gibson

Tokyo

Japan

Minecraft

Action, Arcade

Price and specs

Not enough votes to call it. On the specs, Gemini 3.8 Flash has the edge: bigger model tier, bigger context window, major provider backing. Mercury 2.5 Preview costs 25x less per token.

Gemini 3.8 Flash and Mercury 2.5 Preview compared across 54 shared prompts
SpecGemini 3.8 FlashMercury 2.5 Preview
Input price$0.75/M tokens$0.04/M tokens
Output price$3.75/M tokens$0.15/M tokens
Context window1.0M tokens260K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2026
At 10M a month$7.50$7.50$0.40$0.40
1M10M100M1B10M tokens

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

Where to run it3 hosts, cheapest first
Gemini 3.8 Flash2 hosts
HostInOutContextUptime
  • Google AI Studio$0.75 in·$3.75 out·1M·100% up
  • Google Vertex AI$1.35 in·$6.75 out·1M·99.4% up
Mercury 2.5 Preview1 host
HostInOutContextUptime
  • Inception$0.04 in·$0.15 out·260k·93% up

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between Gemini 3.8 Flash and Mercury 2.5 Preview?

Gemini 3.8 Flash is developed by Google AI while Mercury 2.5 Preview is developed by Inception. Gemini 3.8 Flash has a 1.0M token context window vs Mercury 2.5 Preview's 260K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.8 Flash or Mercury 2.5 Preview?

It depends on your use case. Gemini 3.8 Flash and Mercury 2.5 Preview 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 3.8 Flash cost compared to Mercury 2.5 Preview?

Gemini 3.8 Flash costs $0.75/M input tokens and Mercury 2.5 Preview costs $0.04/M input tokens. Mercury 2.5 Preview is $0.71/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 3.8 Flash and Mercury 2.5 Preview on Rival?

This page shows a side-by-side comparison of Gemini 3.8 Flash and Mercury 2.5 Preview 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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Model pages

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