What is the difference between Claude Sonnet 4 and DeepSeek V4 Flash?

Claude Sonnet 4 is developed by Anthropic while DeepSeek V4 Flash is developed by DeepSeek. Claude Sonnet 4 has a 200K token context window vs DeepSeek V4 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 DeepSeek V4 Flash?

It depends on your use case. Claude Sonnet 4 and DeepSeek V4 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 DeepSeek V4 Flash?

Claude Sonnet 4 costs $3/M input tokens and DeepSeek V4 Flash costs $0.14/M input tokens. DeepSeek V4 Flash is $2.86/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 DeepSeek V4 Flash on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4 and DeepSeek V4 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 Apr 2026

Claude Sonnet 4vsDeepSeek V4 Flash

DeepSeek V4 Flash is cheaper than Claude Sonnet 4 at $0.14/M vs $3/M input tokens.

Claude Sonnet 4 and DeepSeek V4 Flash compared across 53 shared prompts
Spec	Claude Sonnet 4	DeepSeek V4 Flash
Input price	$3/M tokens	$0.14/M tokens
Output price	$15/M tokens	$0.28/M tokens
Context window	200K tokens	1.0M tokens
Weights	Closed	Open
Free API (OpenRouter)	No	No
Released	May 2025	Apr 2026