What is the difference between Gemini 3.8 Flash and GPT-5.1 Chat?

Gemini 3.8 Flash is developed by Google AI while GPT-5.1 Chat is developed by OpenAI. Gemini 3.8 Flash has a 1.0M token context window vs GPT-5.1 Chat's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.8 Flash or GPT-5.1 Chat?

It depends on your use case. Gemini 3.8 Flash and GPT-5.1 Chat each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does Gemini 3.8 Flash cost compared to GPT-5.1 Chat?

Gemini 3.8 Flash costs $0.75/M input tokens and GPT-5.1 Chat costs $1.25/M input tokens. Gemini 3.8 Flash is $0.50/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 3.8 Flash and GPT-5.1 Chat on Rival?

This page shows a side-by-side comparison of Gemini 3.8 Flash and GPT-5.1 Chat 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 Sep 2026

Gemini 3.8 FlashvsGPT-5.1 Chat

Gemini 3.8 Flash is cheaper than GPT-5.1 Chat at $0.75/M vs $1.25/M input tokens.

Gemini 3.8 Flash and GPT-5.1 Chat compared across 52 shared prompts
Spec	Gemini 3.8 Flash	GPT-5.1 Chat
Input price	$0.75/M tokens	$1.25/M tokens
Output price	$3.75/M tokens	$10/M tokens
Context window	1.0M tokens	128K tokens
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	Sep 2026	Nov 2025