The Known Good Updated 25 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
#19 of 61
77based on 4 of 6 evaluations
Known Good Index
Speed
#214 of 316
37.6
Output tokens per second
Price
#217 of 340
$1.35
Blended per 1M tokens
In $0.95 · Out $2.55
Cache hit price
#138 of 206
$0.20
per 1M tokens (−79%)
Context
#189 of 345
205k
tokens (~300 pages)
Z.ai: GLM 5.1 — Z.ai
Quality
#12 of 61
88based on 3 of 6 evaluations
Known Good Index
Speed
#153 of 316
53.6
Output tokens per second
Price
#221 of 340
$1.48
Blended per 1M tokens
In $0.97 · Out $3.04
Cache hit price
#136 of 206
$0.18
per 1M tokens (−81%)
Context
#195 of 345
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 38 tokens per second for Z.ai: GLM 5 and 54 for Z.ai: GLM 5.1, with time to first token at 2.5s and 1.9s. 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 26 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 6 evaluations 88 based on 3 of 6 evaluations
Blended $/1M $1.35 $1.48
Output tok/s 38 54
Context window 205k 205k
Providers 14 19
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Quality

Known Good Index and the capability indices, side by side

IndicesComponents
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
Science Index 92 89
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
MATH / AIME80 / 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 1,470
The Known Good

Price & Cost

Published API pricing by token type

Per token typeCache discount
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 38 54
Time to first token 2.5s 1.9s
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 $1.55 116 — —
GMICloud $0.93 60 $1.50 63
Phala $1.77 57 $1.96 40
Chutes $1.35 49 $1.50 40
Venice $1.55 40 $2.37 69
Baidu · first party $1.08 39 $1.50 54
Parasail $1.55 39 $2.15 73
AtlasCloud $1.50 36 $1.94 44
Novita $1.55 36 $2.13 52
StreamLake $0.93 36 $1.48 22
Z.AI · first party $1.55 33 $2.15 38
SiliconFlow $1.35 30 $1.83 63
DeepInfra $0.97 29 $1.66 61
DigitalOcean $1.16 8 $1.81 18
CoreWeave — — $2.15 125
Friendli — — $2.15 107
Crusoe — — $2.00 91
Fireworks — — $2.15 73
Wafer — — $1.55 54
Nebius — — $2.15 24

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 →