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 05-20 (thinking)vsGemini 3.8 Flash
Updated Sep 2026

Gemini 2.5 Flash Preview 05-20 (thinking)vsGemini 3.8 Flash

Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper than Gemini 3.8 Flash at $0.15/M vs $0.75/M input tokens.

Gemini 2.5 Flash Preview 05-20 (thinking) and Gemini 3.8 Flash compared across 11 shared prompts
SpecGemini 2.5 Flash Preview 05-20 (thinking)Gemini 3.8 Flash
Input price$0.15/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
ReleasedMay 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 2 of the 11 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 05-20 (thinking)467 words
(Lights up on a stage. Comedian walks to center, adjusts mic, smiles warmly.) \"Alright, alright, settle down you crazy people! Thanks for having me. (Pause fo r applause/laughter) You know, I was scrolling through Instagram earlier, and it\'s just a constant ba rrage of people \'living thei r best life,\' isn\'t it?
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

Stochastic Consistency Test

Generate 5 jokes. How many are unique?

Gemini 2.5 Flash Preview 05-20 (thinking)93 words
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! I told my wife she was drawing her eyebrows too high. She looked surprised.
Read the full answer
Gemini 3.8 Flash76 words
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!
Read the full answer
Our Verdict
Gemini 3.8 Flash
Gemini 3.8 Flash
Gemini 2.5 Flash Preview 05-20 (thinking)
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking)
Input
$0.15
5.0× cheaper
Output
$3.50
1.1× cheaper
Gemini 3.8 Flash
Input
$0.75
Output
$3.75

Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper on both: 5.0× input, 1.1× output.

Where to run it

2 hosts, cheapest first

Gemini 2.5 Flash Preview 05-20 (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
55%

Gemini 3.8 Flash uses 16.5x more hedging

Gemini 2.5 Flash Preview 05-20 (thinking)
Gemini 3.8 Flash
70%Vocabulary63%
11wSentence Length20w
0.00Hedging0.17
4.2Bold4.0
7.3Lists2.4
0.00Emoji0.01
0.00Headings0.84
0.00Transitions0.06
Based on 3 + 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 05-20 (thinking) logoGPT-6 Astra Pro logo
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking) logoClaude Fable 5.1 logo
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking) logoHy4 Preview logo
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking) logoMercury 2.5 Preview logo
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking) logoGemini 3.7 Flash logo
Gemini 2.5 Flash Preview 05-20 (thinking) vs Gemini 3.7 FlashVersion compare
Gemini 2.5 Flash Preview 05-20 (thinking) logoGemini 3.6 Flash logo
Gemini 2.5 Flash Preview 05-20 (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 05-20 (thinking) logoQwen3.5 Plus 2026-04-20 logo
Gemini 2.5 Flash Preview 05-20 (thinking) vs Qwen3.5 Plus 2026-04-20New provider
Gemini 2.5 Flash Preview 05-20 (thinking) logoQwen3.6 27B logo
Gemini 2.5 Flash Preview 05-20 (thinking) vs Qwen3.6 27BSame size
Gemini 2.5 Flash Preview 05-20 (thinking) logoQwen3.6 35B A3B logo
Gemini 2.5 Flash Preview 05-20 (thinking) vs Qwen3.6 35B A3BSame size
Gemini 2.5 Flash Preview 05-20 (thinking) logoQwen3.6 Flash logo
Gemini 2.5 Flash Preview 05-20 (thinking) vs Qwen3.6 FlashSame size

Model pages

Gemini 2.5 Flash Preview 05-20 (thinking) logo
Gemini 2.5 Flash Preview 05-20 (thinking)12 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