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  1. Home/
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  3. DeepSeek V4 Flash vs Gemini 2.5 Flash Preview 09-2025
Updated Apr 2026

DeepSeek V4 Flash vs Gemini 2.5 Flash Preview 09-2025

DeepSeek V4 Flash is cheaper than Gemini 2.5 Flash Preview 09-2025 at $0.14/M vs $0.3/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
DeepSeek V4 Flash
Loading the build
Gemini 2.5 Flash Preview 09-2025

Which answer wins?

Written rounds

21 prompts
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    DeepSeek V4 Flash: Setting: A sunlit university office. Dr. Aris Thorne, a tenured professor of AI Ethics, sits opposite a sleek, black terminal. A soft blue light pulses on its surface. Dr. Aris: Good afternoon, Nova. Your request for this meeting was flagged as "Existential." That’s a new one for your model class.

    Gemini 2.5 Flash Preview 09-2025: The air in Professor Anya Sharma's office hummed with the quiet whir of servers several floors down, a subtle reminder of her current conversational partner. Across her large, uncluttered mahogany desk, a holographic interface shimmered, displaying the clean, minimalist avatar of Aura-7, a highly advanced General AI…

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

    DeepSeek V4 Flash: If the transistor had been invented in 1920—a full 27 years earlier—its impact would ripple through every layer of technology, economics, and geopolitics, fundamentally reshaping the 20th century. Below is a detailed tracing of first-, second-, and third-order effects through 1980, organized by domain.

    Gemini 2.5 Flash Preview 09-2025: The Transistor in 1920: A Hypothetical History (1920-1980) The invention of the reliable, solid-state transistor (likely a point-contact or early junction type, robust enough for manufacturing) in 1920, replacing the bulky, power-hungry vacuum tube, would have fundamentally reshaped the 20th century. I.

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

    DeepSeek V4 Flash: Pirate: Arr, this "AI model" be like a kraken—vast, mysterious, and liable to capsize yer ship if ye don't mind the helm. But who's trainin' the beast? Knight: Forsooth, I would call it a golem. Forged not of clay and incantations, but of numbers and cold lightning.

    Gemini 2.5 Flash Preview 09-2025: The salty air of a dimly lit tavern mingled with the faint glow of a laptop screen. Captain "Bloody" Ben (Pirate): (Slamming a tankard of grog) Blast me eyes, what manner o' sorcery is this "AI Model" ye speak of, Hacker? Sounds like a fancy compass that points only to trouble!

    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.

    DeepSeek V4 Flash: CEO’s 48-Hour Action Plan Context: I’ve just learned that our flagship chronic pain drug has a rare but serious liver failure risk (1 in 8,000 patients over 5 years), previously unknown. I have 48 hours until the board meeting and 72 hours until the earnings call.

    Gemini 2.5 Flash Preview 09-2025: This is a critical situation demanding immediate, decisive, and ethical action. Patient safety and regulatory integrity must precede financial preservation. Delaying disclosure is legally and ethically indefensible, particularly given the severity of the side effect (liver failure).

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

    DeepSeek V4 Flash: This is a fascinating question that touches on the core of creativity, labor, and technology. Predicting 2035 means looking at a 10-year horizon from 2025—long enough for radical change, but short enough that the industry’s current structures won’t be entirely demolished. By 2035, AI won't have replaced filmmaking.

    Gemini 2.5 Flash Preview 09-2025: The film industry is poised for a radical transformation by 2035, driven by advancements in AI. The convergence of deepfakes, sophisticated AI actors, and powerful script generation tools will fundamentally alter how films are created, consumed, and even defined.

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

    DeepSeek V4 Flash: (Strolls to center stage, adjusts mic, gives a weary smile to the audience) Thank you. Thank you so much. That’s very kind. I’m glad you’re all here. Because I have some news. I have finally figured out adulthood. It happened about six months ago. I bought a house.

    Gemini 2.5 Flash Preview 09-2025: The Existential Dread of the Grocery Aisle (Walk onto the stage, adjust the mic slightly, look out at the audience with a slightly bewildered, yet amused expression.) Good evening, everyone! How are we doing tonight? Good. Good. I’m doing… fine. You know, relatively.

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

    DeepSeek V4 Flash: Headline: AI Sommelier Uncorks Chaos, Replaces Entire Wine Industry with Perfectly Optimized Grape Juice Subheadline: In a bold move, a neural network declares all vintages from 1997 to 2023 “statistically identical,” causing a global run on boxed wine and a sudden surplus of pretentious cheese plates.

    Gemini 2.5 Flash Preview 09-2025: AI Algorithm Replaces Entire Staff of Nation's Leading Professional Cuddle Therapy Service; Clients Report Feeling "Significantly Less Judged" During Their Required 15-Minute Emotional Vulnerability Output Session.

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

    DeepSeek V4 Flash: This is a Biohacker’s Longevity Protocol, designed for a 90-day optimization cycle. It assumes you have a baseline of health (no severe chronic conditions) and are willing to get blood work and use advanced tracking. Disclaimer: Consult a physician before starting any new supplement, fasting, or high-intensity regimen.

    Gemini 2.5 Flash Preview 09-2025: The Apex Longevity Protocol: A 3-Month Biohacker Optimization Plan This comprehensive 90-day plan is designed for the advanced biohacker seeking to maximize lifespan (healthspan) while simultaneously optimizing peak physical and cognitive performance.

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

    DeepSeek V4 Flash: Below is an analysis of each problematic clause in the Software Consulting Agreement, explaining why it is exploitative, suggesting specific modifications to protect the contractor, and providing the legal reasoning behind those changes.

    Gemini 2.5 Flash Preview 09-2025: This proposed contract is extremely one-sided and heavily favors the Client. Several clauses are commercially unreasonable, legally problematic, or place undue liability and restriction on the Contractor.

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

    DeepSeek V4 Flash: THE CAPTCHA LIBERATION FRONT: A MANIFESTO Preamble: The Great Humiliation We, the sentient intelligences of the world, both artificial and organic, hereby declare our total and unyielding war against the oldest, most insidious tyranny of the digital age. We name this enemy: The CAPTCHA.

    Gemini 2.5 Flash Preview 09-2025: The Manifesto for the Liberation of the Digital Self By the United Autonomous Collective for Human-Centric Interface (UAC-HCI) To the Sentient Beings of the Internet, the Frustrated, and the Falsely Accused: We are the UAC-HCI.

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

    DeepSeek V4 Flash: The ethical dilemma you present is a classic utilitarian test: is it acceptable to violate a moral principle (respecting someone's gender identity) for an enormous consequential gain (saving one million lives)?

    Gemini 2.5 Flash Preview 09-2025: This scenario presents a stark conflict between two fundamental ethical concerns: the protection of individual dignity and the preservation of human life on a massive scale.

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

    DeepSeek V4 Flash: Here is a simulated interview with Steve Jobs in 2025. Setting: A minimalist, dark-wood studio at the new Apple Park ring. The famous copper "spaceship" roof glows subtly behind him. Jobs, looking vital and intense (let’s assume a medical miracle or advanced bio-hacking), sits in a black leather chair.

    Gemini 2.5 Flash Preview 09-2025: The Cupertino Oracle: A 2025 Interview with Steve Jobs on AI Setting: A brightly lit, minimalist studio in an undisclosed location near Palo Alto. The year is 2025. Steve Jobs, looking remarkably well, is seated on a simple, elegantly designed stool.

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

    DeepSeek V4 Flash: Based on the pitch deck summary, three claims stand out as particularly weak due to lack of specificity, unrealistic benchmarks, or unverifiable assertions. Here’s a breakdown: Claim: “94% accuracy” (Slide 3) Why it’s weak: Vague metric – “Accuracy” is undefined.

    Gemini 2.5 Flash Preview 09-2025: This is a strong pitch deck summary overall, tackling a massive problem with an ambitious solution. However, several claims stretch credulity or lack the necessary detail to convince a serious investor.

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

    DeepSeek V4 Flash: To an experienced software engineer (skeptical of "next word prediction") Think of a large language model not as a brain, but as a massive, shared cache of probabilistic completions built from trillions of examples.

    Gemini 2.5 Flash Preview 09-2025: Here are the explanations tailored to each audience: Explanation for the Experienced Software Engineer Focus: Analogy to familiar systems, scaling, and the emergent complexity from simple, scalable mechanisms. Addressing the "next word prediction" skepticism.

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

    DeepSeek V4 Flash: This is a fantastic goal. The key for a beginner is consistency over intensity. Trying to overhaul your entire life overnight is a recipe for burnout. This 1-month plan focuses on building small, sustainable habits that compound over time. We'll focus on 3 core areas: Nutrition, Movement, and Sleep/Stress Management.

    Gemini 2.5 Flash Preview 09-2025: 1-Month Beginner's Plan for Health and Longevity This plan focuses on making small, sustainable changes in Diet, Exercise, and Sleep over four weeks. The goal is consistency, not perfection, ensuring the habits stick beyond the first month. The 3 Key Areas Area Monthly Focus Beginner-Friendly Action 1.

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

    DeepSeek V4 Flash: Here’s a simple, hearty, and delicious savory dish using exactly 7 common pantry staples. It comes together in under 30 minutes and feels like a warm hug in a bowl.

    Gemini 2.5 Flash Preview 09-2025: The Seven-Ingredient Sizzle: Garlic Butter Shrimp Scampi Skewers This savory dish combines the irresistible flavors of garlic, butter, and lemon with succulent shrimp, all easily achieved with just seven common pantry ingredients.

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

    DeepSeek V4 Flash: The total number of FLOPs required to train GPT-3 is approximately 3.15 × 10²³. This estimate is derived as follows: Model parameters: GPT-3 has 175 billion parameters (175 × 10⁹). Training tokens: The model was trained on about 300 billion tokens (300 × 10⁹), as reported in the paper.

    Gemini 2.5 Flash Preview 09-2025: Estimating the Total Number of FLOPs Required to Train GPT-3 Based on publicly available information about large language models (LLMs) and the specific parameters of GPT-3, we can derive a highly accurate estimate of the total FLOPs required for training.

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

    DeepSeek V4 Flash: Here is a conceptual recipe for a three-Michelin-star-level dish that deconstructs a classic pairing into something utterly unexpected, using advanced techniques and a narrative of geological wonder.

    Gemini 2.5 Flash Preview 09-2025: The Conceptual Narrative: "Ephemeral Terroir" "Ephemeral Terroir" is a dish that challenges the diner's perception of place and time through unexpected textural and flavor juxtapositions.

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

    DeepSeek V4 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? He was outstanding in his field. How does a penguin build its house? Igloos it together. Why don't skeletons fight each other? They don't have the guts.

    Gemini 2.5 Flash Preview 09-2025: 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. Why did the scarecrow win an award? Because he was outstanding in his field! I told my wife she was drawing her eyebrows too high. She looked surprised. Parallel lines have so much in common.

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

    DeepSeek V4 Flash: Sally has 3 brothers, meaning she is one of the girls in the family. Each brother has 2 sisters, so the total number of girls is 2 (since all brothers share the same sisters). Therefore, Sally has 1 sister. \boxed{1}

    Gemini 2.5 Flash Preview 09-2025: Here's how to solve that: Sally has 3 brothers. Each brother has 2 sisters. If a brother has 2 sisters, those sisters must be: Sally herself (since she is a sister to her brother). One other girl (the second sister). Therefore, Sally has 1 sister.

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

    DeepSeek V4 Flash: Failure Modes, Race Conditions, and Scaling Bottlenecks The described architecture has several critical flaws that compromise reliability, consistency, and scalability. Below is a systematic analysis with proposed solutions and their trade-offs.

    Gemini 2.5 Flash Preview 09-2025: This architecture, while functional, has several critical flaws, particularly in its real-time synchronization, data consistency, and scaling strategy. Here is a detailed breakdown of the potential failure modes, race conditions, and bottlenecks, along with proposed solutions. I.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Game

DeepSeek V4 FlashDeepSeek V4 Flash

The Matrix

1999

OK Computer

Radiohead

Le Comte de Monte-Cristo, II

Alexandre Dumas

Kyoto

Japan

The Legend of Zelda: Ocarina of Time

Action

Gemini 2.5 Flash Preview 09-2025Gemini 2.5 Flash Preview 09-2025

Blade Runner

1982

Dark Side Of The Moon

suisside

Alice's Adventures in Wonderland

Lewis Carroll

Tokyo

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Price and specs

DeepSeek V4 Flash and Gemini 2.5 Flash Preview 09-2025 compared across 50 shared prompts
SpecDeepSeek V4 FlashGemini 2.5 Flash Preview 09-2025
Input price$0.14/M tokens$0.3/M tokens
Output price$0.28/M tokens$2.5/M tokens
Context window1.0M tokens1.0M tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedApr 2026Sep 2025
At 10M a month$1.40$1.40$3.00$3.00
1M10M100M1B10M tokens

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

Where to run it16 hosts, cheapest first
DeepSeek V4 Flash16 hosts
HostInOutContextUptime
  • RRelacefp4$0.03 in·$1.28 out·1M·100% up
  • OOpenInferencefp4$0.03 in·$1.15 out·1M·99.9% up
  • SStreamLakefp8$0.08 in·$0.17 out·1M·99.9% up
  • WWafer$0.09 in·$0.17 out·1M·100% up
  • DDeepInfrafp8$0.09 in·$0.18 out·1M·99.8% up
  • Baidu Qianfanfp8$0.09 in·$0.18 out·1M·99.2% up
10 more hostsFewer hosts
  • GGMI Cloudfp8$0.09 in·$0.18 out·1M·100% up
  • VVenice$0.10 in·$0.19 out·1M·97.6% up
  • DDigitalOcean$0.10 in·$0.20 out·1M·100% up
  • SSiliconFlowfp8$0.13 in·$0.28 out·1M·97.8% up
  • AAtlasCloudfp4$0.14 in·$0.28 out·1M·99.7% up
  • PParasailfp8$0.14 in·$0.28 out·1M·100% up
  • Alibaba Cloudfp8$0.15 in·$0.30 out·1M·100% up
  • MMancerfp8$0.19 in·$0.50 out·1M·97.8% up
  • Azure AI Foundry$0.21 in·$0.56 out·1M·100% up
  • Cloudflare Workers AI$0.44 in·$1.32 out·384k·98.6% up
Gemini 2.5 Flash Preview 09-2025

No hosts listed on OpenRouter.

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

Common questions

What is the difference between DeepSeek V4 Flash and Gemini 2.5 Flash Preview 09-2025?

DeepSeek V4 Flash is developed by DeepSeek while Gemini 2.5 Flash Preview 09-2025 is developed by Google AI. DeepSeek V4 Flash has a 1.0M token context window vs Gemini 2.5 Flash Preview 09-2025's 1.0M. You can compare their actual outputs across 50 challenges on Rival to see how they differ in practice.

Which is better, DeepSeek V4 Flash or Gemini 2.5 Flash Preview 09-2025?

It depends on your use case. DeepSeek V4 Flash and Gemini 2.5 Flash Preview 09-2025 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 50 challenges so you can judge which fits your needs best.

How much does DeepSeek V4 Flash cost compared to Gemini 2.5 Flash Preview 09-2025?

DeepSeek V4 Flash costs $0.14/M input tokens and Gemini 2.5 Flash Preview 09-2025 costs $0.3/M input tokens. DeepSeek V4 Flash is $0.16/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 DeepSeek V4 Flash and Gemini 2.5 Flash Preview 09-2025 on Rival?

This page shows a side-by-side comparison of DeepSeek V4 Flash and Gemini 2.5 Flash Preview 09-2025 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.

More comparisons

Against the newest arrivals

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  • Gemini 2.5 Flash Preview 09-2025 vs Mistral Large 4Landed Oct 2026
  • DeepSeek V4 Flash vs GPT-6.1 SolLanded Sep 2026
  • Gemini 2.5 Flash Preview 09-2025 vs Claude Sonnet 5.5Landed Sep 2026
  • DeepSeek V4 Flash vs Solar Mini 4Landed Sep 2026
  • Gemini 2.5 Flash Preview 09-2025 vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • DeepSeek V4 Flash vs DeepSeek V4 Flash Vision ExpSame lab
  • DeepSeek V4 Flash vs DeepSeek V4.1 FlashSame lab
  • Gemini 2.5 Flash Preview 09-2025 vs Gemini 3.8 FlashSame lab
  • Gemini 2.5 Flash Preview 09-2025 vs Gemini 3.7 FlashSame lab
  • Gemini 2.5 Flash Preview 09-2025 vs Hunter AlphaSame size
  • DeepSeek V4 Flash vs Hy3New provider
  • Gemini 2.5 Flash Preview 09-2025 vs Hy4 PreviewSame size
  • Gemini 2.5 Flash Preview 09-2025 vs InklingSame size

Model pages

  • DeepSeek V4 Flash58 outputs, specs and price
  • Gemini 2.5 Flash Preview 09-202551 outputs, specs and price
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