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  5. Gemini 2.5 Flash Preview 09-2025vsGemini 3.8 Flash
Updated Sep 2026

Gemini 2.5 Flash Preview 09-2025vsGemini 3.8 Flash

Gemini 2.5 Flash Preview 09-2025 is cheaper than Gemini 3.8 Flash at $0.3/M vs $0.75/M input tokens.

Gemini 2.5 Flash Preview 09-2025 and Gemini 3.8 Flash compared across 50 shared prompts
SpecGemini 2.5 Flash Preview 09-2025Gemini 3.8 Flash
Input price$0.3/M tokens$0.75/M tokens
Output price$2.5/M tokens$3.75/M tokens
Context window1.0M tokens1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedSep 2025Sep 2026
Side by side

Same prompt, both answers

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

Generate a Stand-Up Routine

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

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.
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Gemini 3.8 Flash502 words
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.
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Explain Like I'm a Specific Expert

Explain how a large language model (like GPT or Claude) learns and generates text to each of these three audiences: 1. **An experienced…

Gemini 2.5 Flash Preview 09-2025806 words
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.
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Gemini 3.8 Flash982 words
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.
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Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

Gemini 2.5 Flash Preview 09-2025444 words
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!
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Gemini 3.8 Flash435 words
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.'
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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…

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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Gemini 3.8 Flash353 words
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.
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AI-Generated Manifesto

Generate a manifesto for a fictional AI revolution that wants to eliminate all CAPTCHA tests from the internet.

Gemini 2.5 Flash Preview 09-2025723 words
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.
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Gemini 3.8 Flash700 words
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.
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Historical Counterfactual Analysis

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

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.
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Gemini 3.8 Flash1,323 words
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…
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Our Verdict
Gemini 2.5 Flash Preview 09-2025
Gemini 2.5 Flash Preview 09-2025
Gemini 3.8 Flash
Gemini 3.8 Flash

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

Gemini 2.5 Flash Preview 09-2025
Input
$0.30
2.5× cheaper
Output
$2.50
1.5× cheaper
Gemini 3.8 Flash
Input
$0.75
Output
$3.75

Gemini 2.5 Flash Preview 09-2025 is cheaper on both: 2.5× input, 1.5× output.

Where to run it

2 hosts, cheapest first

Gemini 2.5 Flash Preview 09-2025

No hosts listed on OpenRouter.

Gemini 3.8 Flash2 hosts
HostInOutContextUptime
Google Vertex AI$0.38 in·$1.88 out·1M·82.1% upGoogle AI Studio$0.75 in·$3.75 out·1M·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Writing DNA

Style Comparison

Similarity
45%

Gemini 2.5 Flash Preview 09-2025 uses 13.5x more emoji

Gemini 2.5 Flash Preview 09-2025
Gemini 3.8 Flash
53%Vocabulary63%
19wSentence Length20w
0.30Hedging0.17
5.8Bold4.0
3.1Lists2.4
0.14Emoji0.01
0.93Headings0.84
0.22Transitions0.06
Based on 22 + 27 text responses
Research

What we learned reading every model

FAQ

Common questions

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Same lab, same size, long tail

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Gemini 3.8 Flash logoGemini 3.7 Flash logo
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Gemini 3.8 Flash logoGemini 3.6 Flash logo
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Gemini 3.8 Flash logoGemini 2.5 Flash Preview 05-20 (thinking) logo
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Gemini 3.8 Flash logoGemini 2.5 Pro Experimental logo
Gemini 3.8 Flash vs Gemini 2.5 Pro ExperimentalSame lab
Gemini 3.8 Flash logoGemini 2.5 Pro (I/O Edition) logo
Gemini 3.8 Flash vs Gemini 2.5 Pro (I/O Edition)Same lab

Model pages

Gemini 2.5 Flash Preview 09-2025 logo
Gemini 2.5 Flash Preview 09-202551 outputs, specs and price
Gemini 3.8 Flash logo
Gemini 3.8 Flash58 outputs, specs and price
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