The Known Good Updated 29 Jul 2026
Z.ai: GLM 5 vs Z.ai: GLM 5.1 ·Z.ai vs Z.ai

Z.ai: GLM 5 vs Z.ai: GLM 5.1 — head-to-head comparison

Z.ai: GLM 5 profile Z.ai: GLM 5.1 profile All comparisons
Z.ai: GLM 5 — Z.ai
Quality
#20 of 62
77based on 4 of 7 evaluations
Known Good Index
Speed
#215 of 317
36.4
Output tokens per second
Price
#232 of 370
$1.35
Blended per 1M tokens
In $0.95 · Out $2.55
Cache hit price
#167 of 238
$0.20
per 1M tokens (−79%)
Context
#216 of 375
205k
tokens (~300 pages)
Z.ai: GLM 5.1 — Z.ai
Quality
#12 of 62
88based on 3 of 7 evaluations
Known Good Index
Speed
#138 of 317
53.0
Output tokens per second
Price
#235 of 370
$1.48
Blended per 1M tokens
In $0.97 · Out $3.04
Cache hit price
#162 of 238
$0.18
per 1M tokens (−81%)
Context
#222 of 375
205k
tokens (~300 pages)
Summary

On the Known Good Index, Z.ai: GLM 5 scores 77 and Z.ai: GLM 5.1 scores 88 — a 11-point lead for Z.ai: GLM 5.1. They share 3 published evaluations, with Z.ai: GLM 5 ahead on 1 and Z.ai: GLM 5.1 ahead on 2.

Blended pricing is $1.35 per 1M tokens for Z.ai: GLM 5 and $1.48 for Z.ai: GLM 5.1, within 10% of each other.

Throughput is 36 tokens per second for Z.ai: GLM 5 and 53 for Z.ai: GLM 5.1, with time to first token at 2.4s and 1.8s. Z.ai: GLM 5 accepts 205k tokens of context against 205k.

Z.ai: GLM 5 is open weights under Open weights (unrestricted); Z.ai: GLM 5.1 is proprietary. 20 tracked hosts serve one or both, and 13 serve both.

Generated from tracked data on 29 Jul 2026 · how these comparisons are computed →

At a glance
MetricZ.ai: GLM 5Z.ai: GLM 5.1
Known Good Index 77 based on 4 of 7 evaluations 88 based on 3 of 7 evaluations
Blended $/1M $1.35 $1.48
Output tok/s 36 53
Context window 205k 205k
Providers 14 19
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Quality

Known Good Index and the capability indices, side by side

Index scores

Each index is min-max normalised across tracked models and scaled 0–100 from published evaluations. We do not run these evaluations.

MetricZ.ai: GLM 5Z.ai: GLM 5.1
Known Good Index 77 88
Coding Index 67 —
Mathematics Index 80 92
Agentic Index 67 82
Openness Index 60 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Z.ai: GLM 5 · marker = Z.ai: GLM 5.1 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond88 / 85
Mock AIME 2024–2580 / 92
SWE-bench Verified72 / 74

Right-hand figures read Z.ai: GLM 5 / Z.ai: GLM 5.1. Z.ai: GLM 5 leads on 1 of 3, Z.ai: GLM 5.1 on 2.

The Known Good

Arena Elo

Human preference rating from blind pairwise votes

Arena ratings

Elo from blind pairwise votes, ingested from Arena. Higher is better.

MetricZ.ai: GLM 5Z.ai: GLM 5.1
Text Arena 1,445 1,465
Text Arena (style controlled) 1,457 1,469
The Known Good

Price & Cost

Published API pricing by token type

Published pricing

USD per 1M tokens. Blended is a 3:1 input:output mix. Live from OpenRouter, cross-checked against models.dev. Lower is better.

MetricZ.ai: GLM 5Z.ai: GLM 5.1
Input $/1M $0.95 $0.97
Output $/1M $2.55 $3.04
Blended $/1M $1.35 $1.48
Cache read $/1M $0.200 $0.179
The Known Good
We publish blended price rather than cost-per-task. Cost-per-task requires token counts from an evaluation suite we do not run. Blended price is computed from published rates and is fully reproducible — see the pricing methodology.

Context Window

Maximum input accepted and maximum output emitted

Context and output limits

Provider-declared limits, from metadata via models.dev and OpenRouter. Higher is better.

MetricZ.ai: GLM 5Z.ai: GLM 5.1
Context window 205k 205k
Max output tokens 131k 128k
The Known Good

Speed & Latency

Median throughput and time to first token across hosting providers

Output speedTime to first token
Throughput and latency

Medians across all tracked providers, derived from OpenRouter endpoint telemetry.

MetricZ.ai: GLM 5Z.ai: GLM 5.1
Output tokens/s 36 53
Time to first token 2.4s 1.8s
The Known Good

Providers

Which hosts serve each model, and at what price and speed

20 hosts · 13 serve both
Full provider benchmarks →
Provider Z.ai: GLM 5 blendedZ.ai: GLM 5 tok/s Z.ai: GLM 5.1 blendedZ.ai: GLM 5.1 tok/s
Amazon Bedrock · first party $1.55 96 — —
DeepInfra $0.97 46 $1.66 62
Parasail $1.55 40 $2.15 66
Chutes $1.35 38 $1.50 41
Venice $1.55 38 $2.37 64
AtlasCloud $1.50 37 $1.94 27
StreamLake $0.93 36 $1.48 43
GMICloud $0.93 35 $1.50 66
Baidu · first party $1.08 31 $1.46 42
Z.AI · first party $1.55 31 $2.15 42
Novita $1.55 28 $2.13 51
SiliconFlow $1.35 27 $1.83 57
DigitalOcean $1.16 8 $1.81 20
Phala $1.77 — $1.96 42
CoreWeave — — $2.15 146
Wafer — — $1.55 87
Friendli — — $2.15 59
Crusoe — — $2.00 54
Nebius — — $2.15 29
Fireworks — — $2.15 —

Per-host pricing and telemetry from OpenRouter. A dash means that host does not serve that model.

The Known Good
Sources for this page
Pricing & providers — OpenRouter Metadata — models.dev Benchmarks — Epoch AI (CC-BY 4.0)Elo — Arena Full attribution →