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  5. Gemini 2.5 Flash Preview 05-20 (thinking)vsGPT-5.5
Updated Apr 2026

Gemini 2.5 Flash Preview 05-20 (thinking)vsGPT-5.5

Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper than GPT-5.5 at $0.15/M vs $5/M input tokens.

Gemini 2.5 Flash Preview 05-20 (thinking) and GPT-5.5 compared across 11 shared prompts
SpecGemini 2.5 Flash Preview 05-20 (thinking)GPT-5.5
Input price$0.15/M tokens$5/M tokens
Output price$3.5/M tokens$30/M tokens
Context window1.0M tokens1.1M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedMay 2025Apr 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
GPT-5.5605 words
So I’ve been trying to be healthier lately, which is just a polite way of saying I bought vegetables and watched them die slowly in my refrigerator. Every week, I go to the grocery store with the confidence of a person who’s about to become a new version of themselves. I’m like, “This week? Spinach. Salmon.
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
GPT-5.569 words
Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break, and it said, “No problem—I’ll go to sleep.” Why did the scarecrow win an award? Because he was outstanding in his field. I used to be a baker, but I couldn’t make enough dough. Why can’t you trust stairs?
Read the full answer
Our Verdict
GPT-5.5
GPT-5.5
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, GPT-5.5 has the edge: bigger model tier, newer.

Gemini 2.5 Flash Preview 05-20 (thinking) costs 8.6x less per token.

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
33× cheaper
Output
$3.50
8.6× cheaper
GPT-5.5
Input
$5.00
Output
$30.00

Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper on both: 33× input, 8.6× output.

Where to run it

3 hosts, cheapest first

Gemini 2.5 Flash Preview 05-20 (thinking)

No hosts listed on OpenRouter.

GPT-5.53 hosts
HostInOutContextUptime
Azure AI Foundry$5.00 in·$30.00 out·1.1M·100% upOpenAI$5.00 in·$30.00 out·1.1M·100% upAmazon Bedrock$5.50 in·$33.00 out·1.1M—

Per million tokens. Prices and uptime via OpenRouter, checked 21 Sep 2026.

Writing DNA

Style Comparison

Similarity
40%

GPT-5.5 uses 74.4x more hedging

Gemini 2.5 Flash Preview 05-20 (thinking)
GPT-5.5
70%Vocabulary58%
11wSentence Length18w
0.00Hedging0.74
4.2Bold2.9
7.3Lists5.1
0.00Emoji0.00
0.00Headings1.68
0.00Transitions0.03
Based on 3 + 26 text responses
Research

What we learned reading every model

FAQ

Common questions

Gemini 2.5 Flash Preview 05-20 (thinking) is developed by Google AI while GPT-5.5 is developed by OpenAI. Gemini 2.5 Flash Preview 05-20 (thinking) has a 1.0M token context window vs GPT-5.5's 1.1M. You can compare their actual outputs across 11 challenges on Rival to see how they differ in practice.

It depends on your use case. Gemini 2.5 Flash Preview 05-20 (thinking) and GPT-5.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 11 challenges so you can judge which fits your needs best.

Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens and GPT-5.5 costs $5/M input tokens. Gemini 2.5 Flash Preview 05-20 (thinking) is $4.85/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 Gemini 2.5 Flash Preview 05-20 (thinking) and GPT-5.5 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.

Keep exploring

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Same lab, same size, long tail

Gemini 2.5 Flash Preview 05-20 (thinking) logoGemini 3.8 Flash logo
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Gemini 2.5 Flash Preview 05-20 (thinking) vs Gemini 3.7 FlashVersion compare
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GPT-5.5 vs GPT-6 Astra ProSame lab
GPT-5.5 logoGPT-5.6 Luna logo
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GPT-5.5 logoGPT-4.1 Mini logo
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Model pages

Gemini 2.5 Flash Preview 05-20 (thinking) logo
Gemini 2.5 Flash Preview 05-20 (thinking)12 outputs, specs and price
GPT-5.5 logo
GPT-5.558 outputs, specs and price
Rival
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Explore all of Rival

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