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  5. Gemini 2.5 Flash Preview 05-20vsGPT-5 Pro
Updated Oct 2025

Gemini 2.5 Flash Preview 05-20vsGPT-5 Pro

Gemini 2.5 Flash Preview 05-20 is cheaper than GPT-5 Pro at $0.15/M vs $15/M input tokens.

Gemini 2.5 Flash Preview 05-20 and GPT-5 Pro compared across 6 shared prompts
SpecGemini 2.5 Flash Preview 05-20GPT-5 Pro
Input price$0.15/M tokens$15/M tokens
Output price$0.6/M tokens$120/M tokens
Context window1.0M tokens400K tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedMay 2025Oct 2025
Side by side

Same prompt, both answers

Opening lines from 2 of the 6 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 05-20569 words
Alright, alright, settle down you magnificent collection of human beings! You look good tonight. Not just good, but… like you've all collectively decided to nail the 'I'm here to laugh and avoid talking about my Monday' look. And I respect that. Seriously though, it's great to be back on stage. I'm living the dream.
Read the full answer
GPT-5 Pro650 words
Good to be here. I tried getting healthy, so I bought a smartwatch. Now my wrist is my manager. It vibrates every hour like, “Stand up.” I’m on a crowded bus like, “I’m standing inside three other people right now. Do you want me to levitate?” It reminds me to breathe. Thanks, watch. Incredible tip.
Read the full answer

Stochastic Consistency Test

Generate 5 jokes. How many are unique?

Gemini 2.5 Flash Preview 05-2079 words
Here are 5 jokes for you: 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 Pro88 words
I started labeling my leftovers “Biohazard.” Now nobody steals my lunch and the fridge is treated like a lab. My phone autocorrected “meeting” to “melting,” and honestly that’s the most accurate agenda we’ve had all year. I told my plants I’d water them tomorrow. They leafed me on read.
Read the full answer
Our Verdict
GPT-5 Pro
GPT-5 Pro
Gemini 2.5 Flash Preview 05-20
Gemini 2.5 Flash Preview 05-20Runner-up

Not enough votes to call it. On the specs, GPT-5 Pro has the edge: bigger model tier, newer.

Gemini 2.5 Flash Preview 05-20 costs 200x 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
Input
$0.15
100× cheaper
Output
$0.60
200× cheaper
GPT-5 Pro
Input
$15.00
Output
$120.00

Gemini 2.5 Flash Preview 05-20 is cheaper on both: 100× input, 200× output.

Where to run it

1 host

Gemini 2.5 Flash Preview 05-20

No hosts listed on OpenRouter.

GPT-5 Pro1 host
HostInOutContextUptime
OpenAI$15.00 in·$120.00 out·400k·100% up

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

Writing DNA

Style Comparison

Similarity
58%

Gemini 2.5 Flash Preview 05-20 uses 110.4x more bold

Gemini 2.5 Flash Preview 05-20
GPT-5 Pro
69%Vocabulary65%
10wSentence Length15w
0.26Hedging0.32
1.1Bold0.0
5.5Lists2.9
0.00Emoji0.00
0.00Headings0.00
0.00Transitions0.01
Based on 2 + 11 text responses
Research

What we learned reading every model

FAQ

Common questions

Gemini 2.5 Flash Preview 05-20 is developed by Google AI while GPT-5 Pro is developed by OpenAI. Gemini 2.5 Flash Preview 05-20 has a 1.0M token context window vs GPT-5 Pro's 400K. You can compare their actual outputs across 6 challenges on Rival to see how they differ in practice.

It depends on your use case. Gemini 2.5 Flash Preview 05-20 and GPT-5 Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 6 challenges so you can judge which fits your needs best.

Gemini 2.5 Flash Preview 05-20 costs $0.15/M input tokens and GPT-5 Pro costs $15/M input tokens. Gemini 2.5 Flash Preview 05-20 is $14.85/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 and GPT-5 Pro 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

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Model pages

Gemini 2.5 Flash Preview 05-20 logo
Gemini 2.5 Flash Preview 05-2011 outputs, specs and price
GPT-5 Pro logo
GPT-5 Pro42 outputs, specs and price
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