What is the difference between Claude Sonnet 4.5 and GLM 5.1?

Claude Sonnet 4.5 is developed by Anthropic while GLM 5.1 is developed by Z.ai. Claude Sonnet 4.5 has a 200K token context window vs GLM 5.1's 203K. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or GLM 5.1?

It depends on your use case. Claude Sonnet 4.5 and GLM 5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to GLM 5.1?

Claude Sonnet 4.5 costs $3/M input tokens and GLM 5.1 costs $1.4/M input tokens. GLM 5.1 is $1.60/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 GLM 5.1 on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and GLM 5.1 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 4.5vsGLM 5.1

GLM 5.1 is cheaper than Claude Sonnet 4.5 at $1.4/M vs $3/M input tokens.

Claude Sonnet 4.5 and GLM 5.1 compared across 41 shared prompts
Spec	Claude Sonnet 4.5	GLM 5.1
Input price	$3/M tokens	$1.4/M tokens
Output price	$15/M tokens	$4.4/M tokens
Context window	200K tokens	203K tokens
Weights	Closed	Open
Free API (OpenRouter)	No	No
Released	Sep 2025	Apr 2026