What is the difference between Z.ai: GLM 5.1 and OpenAI o4-mini?

Z.ai: GLM 5.1 is developed by Z-ai while OpenAI o4-mini is developed by OpenAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Z.ai: GLM 5.1 or OpenAI o4-mini?

It depends on your use case. Z.ai: GLM 5.1 and OpenAI o4-mini 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 Z.ai: GLM 5.1 cost compared to OpenAI o4-mini?

Z.ai: GLM 5.1 costs $1.4/M input tokens and OpenAI o4-mini costs $1.1/M input tokens. OpenAI o4-mini is $0.30/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 Z.ai: GLM 5.1 and OpenAI o4-mini on Rival?

This page shows a side-by-side comparison of Z.ai: GLM 5.1 and OpenAI o4-mini 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 Z.ai: GLM 5.1 and OpenAI o4-mini?

Z.ai: GLM 5.1 is developed by Z-ai while OpenAI o4-mini is developed by OpenAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Z.ai: GLM 5.1 or OpenAI o4-mini?

It depends on your use case. Z.ai: GLM 5.1 and OpenAI o4-mini 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 Z.ai: GLM 5.1 cost compared to OpenAI o4-mini?

Z.ai: GLM 5.1 costs $1.4/M input tokens and OpenAI o4-mini costs $1.1/M input tokens. OpenAI o4-mini is $0.30/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 Z.ai: GLM 5.1 and OpenAI o4-mini on Rival?

This page shows a side-by-side comparison of Z.ai: GLM 5.1 and OpenAI o4-mini 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.

Z.ai: GLM 5.1 vs OpenAI o4-mini: Which Is Better?

Updated Apr 2026

Our Verdict

Z.ai: GLM 5.1

OpenAI o4-miniRunner-up

No community votes yet. On paper, Z.ai: GLM 5.1 has the edge — bigger model tier, newer, bigger context window.

Too close to call

API pricing

Cost per 1M tokens

Z.ai: GLM 5.1

Input

$1.40

Output

$4.40

OpenAI o4-mini

Input

$1.10

1.3× cheaper

Output

$4.40

Writing DNA

Style Comparison

Similarity

59%

Z.ai: GLM 5.1 uses 364.7x more bold

Z.ai: GLM 5.1

OpenAI o4-mini

54%Vocabulary73%

18wSentence Length15w

0.31Hedging0.18

3.6Bold0.0

2.6Lists2.1

0.00Emoji0.00

0.43Headings0.00

0.11Transitions0.02

Based on 27 + 10 text responses

Research

What we learned reading every model

Z.ai: GLM 5.1 and OpenAI o4-mini 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

OpenAI o4-mini vs MiniMax M3New provider

Z.ai: GLM 5.1 vs Claude Sonnet 4New provider

OpenAI o4-mini vs Pony AlphaNew provider

Updated Apr 2026

Our Verdict

Z.ai: GLM 5.1

OpenAI o4-miniRunner-up

No community votes yet. On paper, Z.ai: GLM 5.1 has the edge — bigger model tier, newer, bigger context window.

Too close to call

API pricing

Cost per 1M tokens

Z.ai: GLM 5.1

Input

$1.40

Output

$4.40

OpenAI o4-mini

Input

$1.10

1.3× cheaper

Output

$4.40

Writing DNA

Style Comparison

Similarity

59%

Z.ai: GLM 5.1 uses 364.7x more bold

Z.ai: GLM 5.1

OpenAI o4-mini

54%Vocabulary73%

18wSentence Length15w

0.31Hedging0.18

3.6Bold0.0

2.6Lists2.1

0.00Emoji0.00

0.43Headings0.00

0.11Transitions0.02

Based on 27 + 10 text responses

Research

What we learned reading every model

Z.ai: GLM 5.1 and OpenAI o4-mini 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

OpenAI o4-mini vs MiniMax M3New provider

Z.ai: GLM 5.1 vs Claude Sonnet 4New provider

OpenAI o4-mini vs Pony AlphaNew provider