The Known Good Updated 8 Oct 2026 Subscribe
OpenAI: gpt-oss-120b vs Z.ai: GLM 5.2 ·OpenAI vs Z.ai

OpenAI: gpt-oss-120b vs Z.ai: GLM 5.2 — head-to-head comparison

OpenAI: gpt-oss-120b profile Z.ai: GLM 5.2 profile All comparisons
OpenAI: gpt-oss-120b — OpenAI
Quality
#44 of 65
62based on 3 of 7 evaluations
Known Good Index
Speed
#25 of 356
150.7
Output tokens per second
Price
#24 of 504
$0.07
Blended per 1M tokens
In $0.04 · Out $0.17
Cache hit price
unranked
—
per 1M tokens
Context
#408 of 550
131k
tokens (~200 pages)
Z.ai: GLM 5.2 — Z.ai
Quality
#8 of 65
91based on 3 of 7 evaluations
Known Good Index
Speed
#121 of 356
83.3
Output tokens per second
Price
#269 of 504
$0.96
Blended per 1M tokens
In $0.08 · Out $3.60
Cache hit price
#189 of 384
$0.083
per 1M tokens (−1%)
Context
#106 of 550
1.05M
tokens (~1,600 pages)
Summary

On the Known Good Index, OpenAI: gpt-oss-120b scores 62 and Z.ai: GLM 5.2 scores 91 — a 29-point lead for Z.ai: GLM 5.2. They share 2 published evaluations, with OpenAI: gpt-oss-120b ahead on 1 and Z.ai: GLM 5.2 ahead on 1.

Blended pricing is $0.07 per 1M tokens for OpenAI: gpt-oss-120b and $0.96 for Z.ai: GLM 5.2 — OpenAI: gpt-oss-120b is about 13.7× cheaper.

Throughput is 151 tokens per second for OpenAI: gpt-oss-120b and 83 for Z.ai: GLM 5.2, with time to first token at 0.8s and 1.3s. OpenAI: gpt-oss-120b accepts 131k tokens of context against 1.05M.

OpenAI: gpt-oss-120b is open weights under Open weights (unrestricted); Z.ai: GLM 5.2 is open weights under Open weights (unrestricted). 45 tracked hosts serve one or both, and 12 serve both.

Generated from tracked data on 8 Oct 2026 · how these comparisons are computed →

At a glance
MetricOpenAI: gpt-oss-120bZ.ai: GLM 5.2
Known Good Index 62 based on 3 of 7 evaluations 91 based on 3 of 7 evaluations
Blended $/1M $0.07 $0.96
Output tok/s 151 83
Context window 131k 1.05M
Providers 20 37
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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: gpt-oss-120bZ.ai: GLM 5.2
Known Good Index 62 91
Openness Index 60 60
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = OpenAI: gpt-oss-120b · marker = Z.ai: GLM 5.2 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond76 / 92
Mock AIME 2024–2589 / 86

Right-hand figures read OpenAI: gpt-oss-120b / Z.ai: GLM 5.2. OpenAI: gpt-oss-120b leads on 1 of 2, Z.ai: GLM 5.2 on 1.

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: gpt-oss-120bZ.ai: GLM 5.2
Text Arena 1,365 1,464
Text Arena (style controlled) 1,352 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: gpt-oss-120bZ.ai: GLM 5.2
Input $/1M $0.04 $0.08
Output $/1M $0.17 $3.60
Blended $/1M $0.07 $0.96
Cache read $/1M — $0.083
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: gpt-oss-120bZ.ai: GLM 5.2
Context window 131k 1.05M
Max output tokens 118k 944k
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: gpt-oss-120bZ.ai: GLM 5.2
Output tokens/s 151 83
Time to first token 0.8s 1.3s
The Known Good

Providers

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

45 hosts · 12 serve both
Full provider benchmarks →
Provider OpenAI: gpt-oss-120b blendedOpenAI: gpt-oss-120b tok/s Z.ai: GLM 5.2 blendedZ.ai: GLM 5.2 tok/s
Cerebras $0.45 828 — —
Groq $0.26 323 — —
Amazon Bedrock · first party $0.26 290 — —
SambaNova $0.34 264 — —
Nebius $0.26 259 $2.15 150
Crusoe $0.10 190 $2.15 100
BaseTen $0.20 176 $2.15 206
Mara $0.30 172 — —
Novita $0.10 138 $1.00 45
Parasail $0.26 119 $2.15 98
Phala $0.26 116 $1.70 79
DeepInfra $0.07 114 $0.87 75
Google · first party $0.16 108 — —
Together $0.26 88 $2.15 142
AkashML $0.07 61 $1.18 27
DigitalOcean $0.15 44 $1.07 91
Mancer 2 $0.10 43 — —
CoreWeave $0.07 37 $1.18 101
SiliconFlow $0.26 24 $1.83 93
DekaLLM $0.07 22 — —
Decart — — $0.64 203
Reka · first party — — $1.60 149
Inceptron — — $2.14 141
InferenceNet — — $1.25 125
Wafer — — $0.96 121
Friendli — — $2.15 110
Mistral · first party — — $2.15 110
ModelRun — — $3.35 108
Relace — — $1.13 85
Venice — — $2.15 84
Baidu · first party — — $0.29 78
Makora — — $1.14 78
Alibaba · first party — — $1.48 76
Morph — — $1.40 72
Cloudflare — — $1.99 64
AtlasCloud — — $1.44 58
Io Net — — $1.33 56
StreamLake — — $0.86 54
Z.AI · first party — — $2.15 50
GMICloud — — $2.15 42
Sail Research — — $1.16 37
Ambient — — $0.95 30
Ionstream — — $2.15 30
Chutes — — $1.93 4
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 →