What is the difference between Gemini 3.5 Flash and GPT-5 Pro?

Gemini 3.5 Flash is developed by Google AI while GPT-5 Pro is developed by OpenAI. Gemini 3.5 Flash has a 1.0M token context window vs GPT-5 Pro's 400K. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.5 Flash or GPT-5 Pro?

It depends on your use case. Gemini 3.5 Flash and GPT-5 Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How much does Gemini 3.5 Flash cost compared to GPT-5 Pro?

Gemini 3.5 Flash costs $1.5/M input tokens and GPT-5 Pro costs $15/M input tokens. Gemini 3.5 Flash is $13.50/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Gemini 3.5 Flash and GPT-5 Pro on Rival?

This page shows a side-by-side comparison of Gemini 3.5 Flash 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.

What is the difference between Gemini 3.5 Flash and GPT-5 Pro?

Gemini 3.5 Flash is developed by Google AI while GPT-5 Pro is developed by OpenAI. Gemini 3.5 Flash has a 1.0M token context window vs GPT-5 Pro's 400K. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.5 Flash or GPT-5 Pro?

It depends on your use case. Gemini 3.5 Flash and GPT-5 Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How much does Gemini 3.5 Flash cost compared to GPT-5 Pro?

Gemini 3.5 Flash costs $1.5/M input tokens and GPT-5 Pro costs $15/M input tokens. Gemini 3.5 Flash is $13.50/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Gemini 3.5 Flash and GPT-5 Pro on Rival?

This page shows a side-by-side comparison of Gemini 3.5 Flash 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.

Gemini 3.5 Flash vs GPT-5 Pro: Which Is Better?

Updated May 2026

Our Verdict

Gemini 3.5 Flash

GPT-5 Pro

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Gemini 3.5 Flash is 13x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Gemini 3.5 Flash

Input

$1.50

10× cheaper

Output

$9.00

13× cheaper

GPT-5 Pro

Input

$15.00

Output

$120.00

Gemini 3.5 Flash is cheaper on both — 10× input, 13× output

Writing DNA

Style Comparison

Similarity

44%

Gemini 3.5 Flash uses 442.3x more bold

Gemini 3.5 Flash

GPT-5 Pro

59%Vocabulary65%

18wSentence Length15w

0.16Hedging0.32

4.4Bold0.0

3.0Lists2.9

0.00Emoji0.00

0.89Headings0.00

0.11Transitions0.01

Based on 27 + 11 text responses

Research

What we learned reading every model

Gemini 3.5 Flash and GPT-5 Pro have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

GPT-5 Pro vs MiniMax M3New provider

Gemini 3.5 Flash vs GPT-5Cross-provider

GPT-5 Pro vs Llama 4 MaverickNew provider

Updated May 2026

Our Verdict

Gemini 3.5 Flash

GPT-5 Pro

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Gemini 3.5 Flash is 13x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Gemini 3.5 Flash

Input

$1.50

10× cheaper

Output

$9.00

13× cheaper

GPT-5 Pro

Input

$15.00

Output

$120.00

Gemini 3.5 Flash is cheaper on both — 10× input, 13× output

Writing DNA

Style Comparison

Similarity

44%

Gemini 3.5 Flash uses 442.3x more bold

Gemini 3.5 Flash

GPT-5 Pro

59%Vocabulary65%

18wSentence Length15w

0.16Hedging0.32

4.4Bold0.0

3.0Lists2.9

0.00Emoji0.00

0.89Headings0.00

0.11Transitions0.01

Based on 27 + 11 text responses

Research

What we learned reading every model

Gemini 3.5 Flash and GPT-5 Pro have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

GPT-5 Pro vs MiniMax M3New provider

Gemini 3.5 Flash vs GPT-5Cross-provider

GPT-5 Pro vs Llama 4 MaverickNew provider