What is the difference between Claude Opus 4 and Gemini 2.5 Flash Preview?

Claude Opus 4 is developed by Anthropic while Gemini 2.5 Flash Preview is developed by Google AI. Claude Opus 4 has a 200K token context window vs Gemini 2.5 Flash Preview's 1.0M. You can compare their actual outputs across 26 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Gemini 2.5 Flash Preview?

It depends on your use case. Claude Opus 4 and Gemini 2.5 Flash Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 26 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Gemini 2.5 Flash Preview?

Claude Opus 4 costs $15/M input tokens and Gemini 2.5 Flash Preview costs $0.15/M input tokens. Gemini 2.5 Flash Preview is $14.85/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 Opus 4 and Gemini 2.5 Flash Preview on Rival?

This page shows a side-by-side comparison of Claude Opus 4 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 May 2025

Claude Opus 4vsGemini 2.5 Flash Preview

Gemini 2.5 Flash Preview is cheaper than Claude Opus 4 at $0.15/M vs $15/M input tokens.

Claude Opus 4 and Gemini 2.5 Flash Preview compared across 26 shared prompts
Spec	Claude Opus 4	Gemini 2.5 Flash Preview
Input price	$15/M tokens	$0.15/M tokens
Output price	$75/M tokens	$0.6/M tokens
Context window	200K tokens	1.0M tokens
Parameters	Not disclosed	Not disclosed
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	May 2025	Apr 2025
SWE-bench Verified	72.5%	60.4%