The Known Good Updated 9 Sep 2026 Subscribe
OpenAI: o3 Mini vs Z.ai: GLM 5.2 ·OpenAI vs Z.ai

OpenAI: o3 Mini vs Z.ai: GLM 5.2 — head-to-head comparison

OpenAI: o3 Mini profile Z.ai: GLM 5.2 profile All comparisons
OpenAI: o3 Mini — OpenAI
Quality
#14 of 65
86based on 4 of 7 evaluations
Known Good Index
Speed
#36 of 341
118.8
Output tokens per second
Price
#309 of 450
$1.93
Blended per 1M tokens
In $1.10 · Out $4.40
Cache hit price
#322 of 344
$0.55
per 1M tokens (−50%)
Context
#334 of 487
200k
tokens (~300 pages)
Z.ai: GLM 5.2 — Z.ai
Quality
#10 of 65
91based on 3 of 7 evaluations
Known Good Index
Speed
#99 of 341
71.8
Output tokens per second
Price
#274 of 450
$1.48
Blended per 1M tokens
In $0.97 · Out $3.04
Cache hit price
#239 of 344
$0.19
per 1M tokens (−80%)
Context
#86 of 487
1.05M
tokens (~1,600 pages)
Summary

On the Known Good Index, OpenAI: o3 Mini scores 86 and Z.ai: GLM 5.2 scores 91 — a 5-point lead for Z.ai: GLM 5.2. They share 2 published evaluations, with OpenAI: o3 Mini ahead on 0 and Z.ai: GLM 5.2 ahead on 2.

Blended pricing is $1.93 per 1M tokens for OpenAI: o3 Mini and $1.48 for Z.ai: GLM 5.2 — Z.ai: GLM 5.2 is about 1.3× cheaper.

Throughput is 119 tokens per second for OpenAI: o3 Mini and 72 for Z.ai: GLM 5.2, with time to first token at 3.1s and 1.5s. OpenAI: o3 Mini accepts 200k tokens of context against 1.05M.

OpenAI: o3 Mini is proprietary; Z.ai: GLM 5.2 is open weights under Open weights (unrestricted). 36 tracked hosts serve one or both.

Generated from tracked data on 9 Sep 2026 · how these comparisons are computed →

At a glance
MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Known Good Index 86 based on 4 of 7 evaluations 91 based on 3 of 7 evaluations
Blended $/1M $1.93 $1.48
Output tok/s 119 72
Context window 200k 1.05M
Providers 1 35
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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.

MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Known Good Index 86 91
Mathematics Index 88
Reasoning Index 85
Openness Index 5 60
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = OpenAI: o3 Mini · marker = Z.ai: GLM 5.2 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond77 / 92
Mock AIME 2024–2577 / 86

Right-hand figures read OpenAI: o3 Mini / Z.ai: GLM 5.2. OpenAI: o3 Mini leads on 0 of 2, 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.

MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Text Arena 1,319 1,464
Text Arena (style controlled) 1,348 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.

MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Input $/1M $1.10 $0.97
Output $/1M $4.40 $3.04
Blended $/1M $1.93 $1.48
Cache read $/1M $0.550 $0.193
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.

MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Context window 200k 1.05M
Max output tokens 100k 131k
The Known Good

Speed & Latency

Mean throughput and time to first token across hosting providers, over successful measurements from the last 48 hours

Throughput and latency

Means across all tracked providers over successful measurements from the last 48 hours, derived from OpenRouter endpoint telemetry.

MetricOpenAI: o3 MiniZ.ai: GLM 5.2
Output tokens/s 119 72
Time to first token 3.1s 1.5s
The Known Good

Providers

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

36 hosts
Full provider benchmarks →
Provider OpenAI: o3 Mini blendedOpenAI: o3 Mini tok/s Z.ai: GLM 5.2 blendedZ.ai: GLM 5.2 tok/s
OpenAI · first party $1.93 110
Decart $3.23 242
CoreWeave $1.18 115
ModelRun $3.35 108
BaseTen $2.15 95
Friendli $2.15 92
Parasail $2.15 92
Fireworks $2.15 87
Crusoe $2.15 84
Mistral · first party $2.15 79
Makora $1.14 78
Reka · first party $1.76 76
Alibaba · first party $1.48 75
Cloudflare $2.15 74
Baidu · first party $2.15 67
Venice $2.15 64
Io Net $1.33 56
DigitalOcean $1.07 55
DeepInfra $0.76 50
Together $2.15 43
Phala $1.70 42
Ambient $0.95 40
GMICloud $2.15 40
Novita $1.05 39
Wafer $1.94 39
Z.AI · first party $2.15 39
Sail Research $1.16 37
SiliconFlow $1.83 37
StreamLake $1.04 37
Inceptron $1.69 35
AtlasCloud $1.44 31
Ionstream $2.15 30
AkashML $1.18 27
Relace $1.07 22
Morph $1.42 19
Chutes $1.93 4

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 →