What is the difference between Claude Sonnet 4.5 and Mercury?

Claude Sonnet 4.5 is developed by Anthropic while Mercury is developed by Inception. Claude Sonnet 4.5 has a 200K token context window vs Mercury's 32K. You can compare their actual outputs across 43 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or Mercury?

It depends on your use case. Claude Sonnet 4.5 and Mercury each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 43 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to Mercury?

Claude Sonnet 4.5 costs $3/M input tokens and Mercury costs $10/M input tokens. Claude Sonnet 4.5 is $7.00/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 Mercury on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and Mercury 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 4.5vsMercury

Claude Sonnet 4.5 is cheaper than Mercury at $3/M vs $10/M input tokens.

Claude Sonnet 4.5 and Mercury compared across 43 shared prompts
Spec	Claude Sonnet 4.5	Mercury
Input price	$3/M tokens	$10/M tokens
Output price	$15/M tokens	$10/M tokens
Context window	200K tokens	32K tokens
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	Sep 2025	Jun 2025