What is the difference between Claude Sonnet 4.5 and Gemini 2.5 Flash Preview?

Claude Sonnet 4.5 is developed by Anthropic while Gemini 2.5 Flash Preview is developed by Google AI. Claude Sonnet 4.5 has a 200K token context window vs Gemini 2.5 Flash Preview's 1.0M. You can compare their actual outputs across 22 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or Gemini 2.5 Flash Preview?

It depends on your use case. Claude Sonnet 4.5 and Gemini 2.5 Flash Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 22 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to Gemini 2.5 Flash Preview?

Claude Sonnet 4.5 costs $3/M input tokens and Gemini 2.5 Flash Preview costs $0.15/M input tokens. Gemini 2.5 Flash Preview is $2.85/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 4.5 and Gemini 2.5 Flash Preview on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and Gemini 2.5 Flash Preview 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 2025

Claude Sonnet 4.5vsGemini 2.5 Flash Preview

Gemini 2.5 Flash Preview is cheaper than Claude Sonnet 4.5 at $0.15/M vs $3/M input tokens.

Claude Sonnet 4.5 and Gemini 2.5 Flash Preview compared across 22 shared prompts
Spec	Claude Sonnet 4.5	Gemini 2.5 Flash Preview
Input price	$3/M tokens	$0.15/M tokens
Output price	$15/M tokens	$0.6/M tokens
Context window	200K tokens	1.0M tokens
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	Sep 2025	Apr 2025
SWE-bench Verified	77.2%	60.4%