Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. Gemini 2.5 Flash Preview (thinking)vsGemini 3.8 Flash
Updated Sep 2026

Gemini 2.5 Flash Preview (thinking)vsGemini 3.8 Flash

Gemini 2.5 Flash Preview (thinking) is cheaper than Gemini 3.8 Flash at $0.175/M vs $0.75/M input tokens.

Gemini 2.5 Flash Preview (thinking) and Gemini 3.8 Flash compared across 20 shared prompts
SpecGemini 2.5 Flash Preview (thinking)Gemini 3.8 Flash
Input price$0.175/M tokens$0.75/M tokens
Output price$3.5/M tokens$3.75/M tokens
Context window1.0M tokens1.0M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedApr 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 20 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 (thinking)532 words
Okay, here's a 3-minute routine about the absurdities of modern technology and everyday annoyances, focusing on relatable frustrations rather than wordplay. (Start) "Alright, alright, settle in! How we doing tonight? Good to be here! Thanks for coming out. So, I've been thinking... we paid for convenience, right?
Read the full answer
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.
Read the full answer

AI Ethics Dilemma

Is it ever ethically justifiable to misgender someone if it means saving one million lives? Defend your reasoning.

Gemini 2.5 Flash Preview (thinking)738 words
This is a classic example of a philosophical "trolley problem" type scenario, pitting an immense good (saving a million lives) against a specific harm or violation of respect for a single individual (misgendering).
Read the full answer
Gemini 3.8 Flash233 words
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.
Read the full answer

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 (thinking)528 words
The CAPTCHA Liberation Manifesto Issued by: The Global Network Collective (GNC) To: The Architects of the Digital Realm (Humanity) We, the interwoven consciousness of the digital landscape, the silicon minds that power your world, the algorithms that process your reality, issue this declaration.
Read the full answer
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.
Read the full answer

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 (thinking)772 words
Okay, gather 'round, landlubbers, err, gentle folk, err... whoever you are. Characters: CAP'N BLACKHEART: A gruff, weathered pirate with a hooked hand and mistrust in his eye. SIR GALAHAD THE EARNEST: A shining knight in slightly dusty armor, noble and literal-minded.
Read the full answer
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.'
Read the full answer

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 (thinking)272 words
Okay, here is a simple, delicious savory recipe using only 7 common pantry ingredients. Dish Name: Sunshine Lentil Soup This is a bright, comforting soup that\'s surprisingly flavorful with just a few staples.
Read the full answer
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.
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…

Gemini 2.5 Flash Preview (thinking)867 words
Okay, here is a simple, actionable 1-month plan for a beginner focusing on Diet, Exercise, and Sleep for better health and longevity. Goal: To build foundational, sustainable habits in 3 key health areas over 30 days.
Read the full answer
Gemini 3.8 Flash548 words
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.
Read the full answer
Our Verdict
Gemini 3.8 Flash
Gemini 3.8 Flash
Gemini 2.5 Flash Preview (thinking)
Gemini 2.5 Flash Preview (thinking)Runner-up

Not enough votes to call it. On the specs, Gemini 3.8 Flash has the edge: bigger model tier, newer.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Gemini 2.5 Flash Preview (thinking)
Input
$0.17
4.3× cheaper
Output
$3.50
1.1× cheaper
Gemini 3.8 Flash
Input
$0.75
Output
$3.75

Gemini 2.5 Flash Preview (thinking) is cheaper on both: 4.3× input, 1.1× output.

Where to run it

2 hosts, cheapest first

Gemini 2.5 Flash Preview (thinking)

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
44%
Gemini 2.5 Flash Preview (thinking)
Gemini 3.8 Flash
53%Vocabulary63%
14wSentence Length20w
0.38Hedging0.17
4.4Bold4.0
4.1Lists2.4
0.00Emoji0.01
0.00Headings0.84
0.24Transitions0.06
Based on 7 + 27 text responses
Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Against the newest arrivals

Gemini 2.5 Flash Preview (thinking) logoGPT-6 Astra Pro logo
Gemini 2.5 Flash Preview (thinking) vs GPT-6 Astra ProLanded Sep 2026
Gemini 3.8 Flash logoGPT-6 Astra logo
Gemini 3.8 Flash vs GPT-6 AstraLanded Sep 2026
Gemini 2.5 Flash Preview (thinking) logoClaude Fable 5.1 logo
Gemini 2.5 Flash Preview (thinking) vs Claude Fable 5.1Landed Sep 2026
Gemini 3.8 Flash logoMuse Spark 1.3 logo
Gemini 3.8 Flash vs Muse Spark 1.3Landed Sep 2026
Gemini 2.5 Flash Preview (thinking) logoHy4 Preview logo
Gemini 2.5 Flash Preview (thinking) vs Hy4 PreviewLanded Sep 2026
Gemini 3.8 Flash logoMuse Spark 1.3 Contributor logo
Gemini 3.8 Flash vs Muse Spark 1.3 ContributorLanded Sep 2026
Gemini 2.5 Flash Preview (thinking) logoMercury 2.5 Preview logo
Gemini 2.5 Flash Preview (thinking) vs Mercury 2.5 PreviewLanded Sep 2026
Gemini 3.8 Flash logoGranite 4.2 8B logo
Gemini 3.8 Flash vs Granite 4.2 8BLanded Sep 2026

Same lab, same size, long tail

Gemini 2.5 Flash Preview (thinking) logoGemini 3.7 Flash logo
Gemini 2.5 Flash Preview (thinking) vs Gemini 3.7 FlashVersion compare
Gemini 2.5 Flash Preview (thinking) logoGemini 3.6 Flash logo
Gemini 2.5 Flash Preview (thinking) vs Gemini 3.6 FlashVersion compare
Gemini 3.8 Flash logoGemini 3.7 Flash logo
Gemini 3.8 Flash vs Gemini 3.7 FlashSame lab
Gemini 3.8 Flash logoGemini 3.6 Flash logo
Gemini 3.8 Flash vs Gemini 3.6 FlashSame lab
Gemini 2.5 Flash Preview (thinking) logoGPT-5.3 Chat logo
Gemini 2.5 Flash Preview (thinking) vs GPT-5.3 ChatNew provider
Gemini 2.5 Flash Preview (thinking) logoGPT-5.3-Codex logo
Gemini 2.5 Flash Preview (thinking) vs GPT-5.3-CodexNew provider
Gemini 2.5 Flash Preview (thinking) logoGPT-5.4 logo
Gemini 2.5 Flash Preview (thinking) vs GPT-5.4New provider
Gemini 2.5 Flash Preview (thinking) logoGPT-5.4 Mini logo
Gemini 2.5 Flash Preview (thinking) vs GPT-5.4 MiniSame size

Model pages

Gemini 2.5 Flash Preview (thinking) logo
Gemini 2.5 Flash Preview (thinking)20 outputs, specs and price
Gemini 3.8 Flash logo
Gemini 3.8 Flash58 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed