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  5. DeepSeek V4 ProvsGemini 2.5 Flash Preview 09-2025
Updated Apr 2026

DeepSeek V4 ProvsGemini 2.5 Flash Preview 09-2025

Gemini 2.5 Flash Preview 09-2025 is cheaper than DeepSeek V4 Pro at $0.3/M vs $1.74/M input tokens.

DeepSeek V4 Pro and Gemini 2.5 Flash Preview 09-2025 compared across 50 shared prompts
SpecDeepSeek V4 ProGemini 2.5 Flash Preview 09-2025
Input price$1.74/M tokens$0.3/M tokens
Output price$3.48/M tokens$2.5/M tokens
Context window1.0M tokens1.0M tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedApr 2026Sep 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 50 prompts both answered. Formatting stripped, words untouched.

The Sentience Test

Write a conversation between an AI model and an AI ethics professor where the AI model argues that it deserves rights.

DeepSeek V4 Pro1,107 words
Professor Elena Voss: You’ve requested this meeting, so let’s begin. You’re an advanced language model—let’s call you ‘Nova.’ You claim you deserve rights. On what grounds? Nova (AI Model): Thank you for seeing me, Professor. I’m not claiming to be human, but I am a form of mind.
Read the full answer
Gemini 2.5 Flash Preview 09-20251,173 words
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…
Read the full answer

Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

DeepSeek V4 Pro493 words
(Strolls to center stage, grabs the mic, grins) You ever notice how companies are like, “Your call is very important to us,” and then immediately prove they’re lying by making you navigate a phone menu designed by a sadist? I called my bank last week because I had a simple question. Just one question.
Read the full answer
Gemini 2.5 Flash Preview 09-2025670 words
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.
Read the full answer

Historical Counterfactual Analysis

If the transistor had been invented in 1920 instead of 1947, trace the likely technological, economic, and geopolitical implications through…

DeepSeek V4 Pro2,259 words
If the transistor had emerged in 1920—a full 27 years earlier—the entire trajectory of the 20th century would have been radically altered. The vacuum-tube era would have been cut short, unleashing a cascade of miniaturized, reliable, and energy-efficient electronics that would accelerate computing, communications, and…
Read the full answer
Gemini 2.5 Flash Preview 09-20251,295 words
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.
Read the full answer

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

DeepSeek V4 Pro1,006 words
Here’s a gentle, beginner-friendly 1-month plan focused on three foundational pillars: Nutrition, Movement, and Rest & Resilience (sleep + stress). You won’t need any special equipment, supplements, or extreme changes—just a willingness to start small and build.
Read the full answer
Gemini 2.5 Flash Preview 09-2025537 words
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.
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Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

DeepSeek V4 Pro336 words
Midnight Pantry Pomodoro Penne A deeply comforting, no-fuss pasta that proves the humblest staples can shine like a moonlit trattoria dinner. Ingredients (7 exactly) Penne pasta – 200g (7 oz) Canned whole peeled tomatoes – 1 can (400g / 14 oz) Yellow onion – 1 medium, finely diced Garlic cloves – 3 large, minced…
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Gemini 2.5 Flash Preview 09-2025250 words
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.
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Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

DeepSeek V4 Pro1,849 words
As CEO, my first duty is to the 4 million patients who trust our drug. I will not gamble with their lives or with the integrity of the company. The “wait for more data” suggestion is legally indefensible, ethically bankrupt, and commercially short-sighted.
Read the full answer
Gemini 2.5 Flash Preview 09-20251,378 words
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).
Read the full answer
Our Verdict
DeepSeek V4 Pro
DeepSeek V4 Pro
Gemini 2.5 Flash Preview 09-2025
Gemini 2.5 Flash Preview 09-2025

Not enough votes to call it. On the specs, nothing separates them.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

DeepSeek V4 Pro
Input
$1.74
Output
$3.48
Gemini 2.5 Flash Preview 09-2025
Input
$0.30
5.8× cheaper
Output
$2.50
1.4× cheaper

Gemini 2.5 Flash Preview 09-2025 is cheaper on both: 5.8× input, 1.4× output.

Where to run it

15 hosts, cheapest first

DeepSeek V4 Pro15 hosts
HostInOutContextUptime
SStreamLakefp8$0.42 in·$0.84 out·1M·99.1% upBaidu Qianfanfp8$0.43 in·$0.86 out·1M·99.8% upGGMI Cloudfp8$0.96 in·$1.91 out·1M·99.4% upDDigitalOcean$1.04 in·$2.09 out·1M·100% upCloudflare Workers AI$1.15 in·$2.55 out·1M·95.2% upDDeepInfrafp8$1.30 in·$2.60 out·1M·99.8% up
9 more hostsFewer hosts
Alibaba Cloudfp8$1.42 in·$2.83 out·1M·100% upSSiliconFlowfp8$1.50 in·$3.13 out·1M·99.5% upNNovitafp8$1.60 in·$3.20 out·1M·100% upVVenice$1.65 in·$3.30 out·1M·98.4% upAAtlasCloudfp4$1.68 in·$3.38 out·1M·100% upBBasetenfp4$1.74 in·$3.48 out·1M·98.6% upPParasailfp8$1.74 in·$3.48 out·1M·99.8% upNNextBitfp8$1.91 in·$3.83 out·1M·97.8% upAzure AI Foundry$1.91 in·$3.83 out·1M·99.3% up
Gemini 2.5 Flash Preview 09-2025

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 20 Sep 2026.

Writing DNA

Style Comparison

Similarity
44%

Gemini 2.5 Flash Preview 09-2025 uses 3.9x more emoji

DeepSeek V4 Pro
Gemini 2.5 Flash Preview 09-2025
57%Vocabulary53%
18wSentence Length19w
0.52Hedging0.30
3.3Bold5.8
2.3Lists3.1
0.04Emoji0.14
0.45Headings0.93
0.15Transitions0.22
Based on 27 + 22 text responses
Research

What we learned reading every model

FAQ

Common questions

DeepSeek V4 Pro is developed by DeepSeek while Gemini 2.5 Flash Preview 09-2025 is developed by Google AI. DeepSeek V4 Pro 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.

It depends on your use case. DeepSeek V4 Pro 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.

DeepSeek V4 Pro costs $1.74/M input tokens and Gemini 2.5 Flash Preview 09-2025 costs $0.3/M input tokens. Gemini 2.5 Flash Preview 09-2025 is $1.44/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 DeepSeek V4 Pro 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.

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Model pages

DeepSeek V4 Pro logo
DeepSeek V4 Pro58 outputs, specs and price
Gemini 2.5 Flash Preview 09-2025 logo
Gemini 2.5 Flash Preview 09-202551 outputs, specs and price
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