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.

Updated May 2026

Gemini 3.5 FlashvsGPT-5 Pro

Gemini 3.5 Flash is cheaper than GPT-5 Pro at $1.5/M vs $15/M input tokens.

Gemini 3.5 Flash and GPT-5 Pro compared across 41 shared prompts
Spec	Gemini 3.5 Flash	GPT-5 Pro
Input price	$1.5/M tokens	$15/M tokens
Output price	$9/M tokens	$120/M tokens
Context window	1.0M tokens	400K tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	May 2026	Oct 2025