What is the difference between Claude Sonnet 4 and Gemini 3.8 Flash?

Claude Sonnet 4 is developed by Anthropic while Gemini 3.8 Flash is developed by Google AI. Claude Sonnet 4 has a 200K token context window vs Gemini 3.8 Flash's 1.0M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4 or Gemini 3.8 Flash?

It depends on your use case. Claude Sonnet 4 and Gemini 3.8 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4 cost compared to Gemini 3.8 Flash?

Claude Sonnet 4 costs $3/M input tokens and Gemini 3.8 Flash costs $0.75/M input tokens. Gemini 3.8 Flash is $2.25/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 Claude Sonnet 4 and Gemini 3.8 Flash on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4 and Gemini 3.8 Flash 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

Claude Sonnet 4vsGemini 3.8 Flash

Gemini 3.8 Flash is cheaper than Claude Sonnet 4 at $0.75/M vs $3/M input tokens.

Claude Sonnet 4 and Gemini 3.8 Flash compared across 53 shared prompts
Spec	Claude Sonnet 4	Gemini 3.8 Flash
Input price	$3/M tokens	$0.75/M tokens
Output price	$15/M tokens	$3.75/M tokens
Context window	200K tokens	1.0M tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	May 2025	Sep 2026