The Known Good Updated 25 Jul 2026
Z.ai: GLM 5.1 vs Z.ai: GLM 5.2 ·Z.ai vs Z.ai

Z.ai: GLM 5.1 vs Z.ai: GLM 5.2 — head-to-head comparison

Z.ai: GLM 5.1 profile Z.ai: GLM 5.2 profile All comparisons
Z.ai: GLM 5.1 — Z.ai
Quality
#12 of 61
88based on 3 of 6 evaluations
Known Good Index
Speed
#154 of 316
53.4
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)
Z.ai: GLM 5.2 — Z.ai
Quality
#8 of 61
91based on 3 of 6 evaluations
Known Good Index
Speed
#147 of 316
55.2
Output tokens per second
Price
#204 of 340
$1.07
Blended per 1M tokens
In $0.70 · Out $2.20
Cache hit price
#115 of 206
$0.13
per 1M tokens (−81%)
Context
#45 of 345
1.05M
tokens (~1,600 pages)
Summary

On the Known Good Index, Z.ai: GLM 5.1 scores 88 and Z.ai: GLM 5.2 scores 91 — a 4-point lead for Z.ai: GLM 5.2. They share 3 published evaluations, with Z.ai: GLM 5.1 ahead on 1 and Z.ai: GLM 5.2 ahead on 2.

Blended pricing is $1.48 per 1M tokens for Z.ai: GLM 5.1 and $1.07 for Z.ai: GLM 5.2 — Z.ai: GLM 5.2 is about 1.4× cheaper.

Throughput is 53 tokens per second for Z.ai: GLM 5.1 and 55 for Z.ai: GLM 5.2, with time to first token at 1.9s and 1.7s. Z.ai: GLM 5.1 accepts 205k tokens of context against 1.05M.

Z.ai: GLM 5.1 is proprietary; Z.ai: GLM 5.2 is open weights under Open weights (unrestricted). 31 tracked hosts serve one or both, and 17 serve both.

Generated from tracked data on 25 Jul 2026 · how these comparisons are computed →

At a glance
MetricZ.ai: GLM 5.1Z.ai: GLM 5.2
Known Good Index 88 based on 3 of 6 evaluations 91 based on 3 of 6 evaluations
Blended $/1M $1.48 $1.07
Output tok/s 53 55
Context window 205k 1.05M
Providers 19 29
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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 5.1Z.ai: GLM 5.2
Known Good Index 88 91
Mathematics Index 92 86
Science Index 89 97
Agentic Index 82 91
Openness Index 5 60
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Z.ai: GLM 5.1 · marker = Z.ai: GLM 5.2 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond85 / 92
MATH / AIME92 / 86
SWE-bench Verified74 / 79

Right-hand figures read Z.ai: GLM 5.1 / Z.ai: GLM 5.2. Z.ai: GLM 5.1 leads on 1 of 3, Z.ai: GLM 5.2 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 5.1Z.ai: GLM 5.2
Text Arena 1,465 1,464
Text Arena (style controlled) 1,470 1,469
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 5.1Z.ai: GLM 5.2
Input $/1M $0.97 $0.70
Output $/1M $3.04 $2.20
Blended $/1M $1.48 $1.07
Cache read $/1M $0.179 $0.130
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 5.1Z.ai: GLM 5.2
Context window 205k 1.05M
Max output tokens 128k 131k
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 5.1Z.ai: GLM 5.2
Output tokens/s 53 55
Time to first token 1.9s 1.7s
The Known Good

Providers

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

31 hosts · 17 serve both
Full provider benchmarks →
Provider Z.ai: GLM 5.1 blendedZ.ai: GLM 5.1 tok/s Z.ai: GLM 5.2 blendedZ.ai: GLM 5.2 tok/s
CoreWeave $2.15 120 $1.18 49
Friendli $2.15 109 $2.15 124
Crusoe $2.00 91 — —
Fireworks $2.15 90 $2.15 123
Venice $2.37 80 $2.15 56
GMICloud $1.50 77 $1.42 50
Parasail $2.15 71 $2.15 45
DeepInfra $1.66 66 $1.45 68
SiliconFlow $1.83 62 $2.00 49
Novita $2.13 52 $1.07 39
Baidu · first party $1.50 51 $1.12 42
Wafer $1.55 50 $2.15 108
Chutes $1.50 48 $1.93 57
AtlasCloud $1.94 42 $1.94 34
Z.AI · first party $2.15 37 $2.15 49
Nebius $2.15 26 — —
StreamLake $1.48 25 $1.07 45
DigitalOcean $1.81 21 $1.89 23
Phala $1.96 — $2.15 48
BaseTen — — $2.15 120
Ionstream — — $2.15 108
Cloudflare — — $2.15 84
Ambient — — $1.89 78
Decart — — $1.52 71
Alibaba · first party — — $1.27 65
Together — — $2.15 62
Morph — — $1.85 52
Inceptron — — $1.43 34
AkashML — — $1.18 33
Io Net — — $4.40 28
Sail Research — — $1.72 27

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 →