What is the difference between Claude Sonnet 4.5 and OpenRouter Fusion · Budget (Jun 2026)?

Claude Sonnet 4.5 is developed by Anthropic while OpenRouter Fusion · Budget (Jun 2026) is developed by OpenRouter. Claude Sonnet 4.5 has a 200K token context window vs OpenRouter Fusion · Budget (Jun 2026)'s 256K. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or OpenRouter Fusion · Budget (Jun 2026)?

It depends on your use case. Claude Sonnet 4.5 and OpenRouter Fusion · Budget (Jun 2026) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How can I compare Claude Sonnet 4.5 and OpenRouter Fusion · Budget (Jun 2026) on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and OpenRouter Fusion · Budget (Jun 2026) 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 Jun 2026

Claude Sonnet 4.5vsOpenRouter Fusion · Budget (Jun 2026)

OpenRouter Fusion · Budget (Jun 2026) has a larger context window than Claude Sonnet 4.5 (256K tokens vs 200K tokens).

Claude Sonnet 4.5 and OpenRouter Fusion · Budget (Jun 2026) compared across 34 shared prompts
Spec	Claude Sonnet 4.5	OpenRouter Fusion · Budget (Jun 2026)
Input price	$3/M tokens	—
Output price	$15/M tokens	—
Context window	200K tokens	256K tokens
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	Sep 2025	Jun 2026