What is the difference between Claude Opus 4 and Z.ai: GLM 5.1?

Claude Opus 4 is developed by Anthropic while Z.ai: GLM 5.1 is developed by Z-ai. Claude Opus 4 has a 200K token context window vs Z.ai: GLM 5.1's 203K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Z.ai: GLM 5.1?

It depends on your use case. Claude Opus 4 and Z.ai: GLM 5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Z.ai: GLM 5.1?

Claude Opus 4 costs $15/M input tokens and Z.ai: GLM 5.1 costs $1.4/M input tokens. Z.ai: GLM 5.1 is $13.60/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 Opus 4 and Z.ai: GLM 5.1 on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Z.ai: 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.

What is the difference between Claude Opus 4 and Z.ai: GLM 5.1?

Claude Opus 4 is developed by Anthropic while Z.ai: GLM 5.1 is developed by Z-ai. Claude Opus 4 has a 200K token context window vs Z.ai: GLM 5.1's 203K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or Z.ai: GLM 5.1?

It depends on your use case. Claude Opus 4 and Z.ai: GLM 5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to Z.ai: GLM 5.1?

Claude Opus 4 costs $15/M input tokens and Z.ai: GLM 5.1 costs $1.4/M input tokens. Z.ai: GLM 5.1 is $13.60/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 Opus 4 and Z.ai: GLM 5.1 on Rival?

This page shows a side-by-side comparison of Claude Opus 4 and Z.ai: 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.

Claude Opus 4 vs Z.ai: GLM 5.1: Which Is Better?

Updated Apr 2026

Our Verdict

Claude Opus 4

Z.ai: GLM 5.1Runner-up

No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, major provider backing.

Z.ai: GLM 5.1 is 17x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4

Input

$15.00

Output

$75.00

Z.ai: GLM 5.1

Input

$1.40

11× cheaper

Output

$4.40

17× cheaper

Z.ai: GLM 5.1 is cheaper on both — 11× input, 17× output

Writing DNA

Style Comparison

Similarity

42%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Z.ai: GLM 5.1

64%Vocabulary54%

62wSentence Length18w

0.52Hedging0.31

4.4Bold3.6

9.1Lists2.6

0.11Emoji0.00

1.87Headings0.43

0.27Transitions0.11

Based on 16 + 27 text responses

Research

What we learned reading every model

Claude Opus 4 and Z.ai: GLM 5.1 have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

Claude Opus 4 vs MiniMax M3New provider

Z.ai: GLM 5.1 vs GPT-5New provider

Z.ai: GLM 5.1 vs Claude Sonnet 4Cross-provider

Updated Apr 2026

Our Verdict

Claude Opus 4

Z.ai: GLM 5.1Runner-up

No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, major provider backing.

Z.ai: GLM 5.1 is 17x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4

Input

$15.00

Output

$75.00

Z.ai: GLM 5.1

Input

$1.40

11× cheaper

Output

$4.40

17× cheaper

Z.ai: GLM 5.1 is cheaper on both — 11× input, 17× output

Writing DNA

Style Comparison

Similarity

42%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4

Z.ai: GLM 5.1

64%Vocabulary54%

62wSentence Length18w

0.52Hedging0.31

4.4Bold3.6

9.1Lists2.6

0.11Emoji0.00

1.87Headings0.43

0.27Transitions0.11

Based on 16 + 27 text responses

Research

What we learned reading every model

Claude Opus 4 and Z.ai: GLM 5.1 have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

Claude Opus 4 vs MiniMax M3New provider

Z.ai: GLM 5.1 vs GPT-5New provider

Z.ai: GLM 5.1 vs Claude Sonnet 4Cross-provider