The Known Good Updated 29 Jul 2026
Anthropic: Claude Sonnet 4.6 vs Z.ai: GLM 5.1 ·Anthropic vs Z.ai

Anthropic: Claude Sonnet 4.6 vs Z.ai: GLM 5.1 — head-to-head comparison

Anthropic: Claude Sonnet 4.6 profile Z.ai: GLM 5.1 profile All comparisons
Anthropic: Claude Sonnet 4.6 — Anthropic
Quality
#17 of 62
80based on 4 of 7 evaluations
Known Good Index
Speed
#182 of 317
43.9
Output tokens per second
Price
#329 of 370
$6.00
Blended per 1M tokens
In $3.00 · Out $15.00
Cache hit price
#195 of 238
$0.30
per 1M tokens (−90%)
Context
#73 of 375
1.00M
tokens (~1,500 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, Anthropic: Claude Sonnet 4.6 scores 80 and Z.ai: GLM 5.1 scores 88 — a 8-point lead for Z.ai: GLM 5.1. They share 3 published evaluations, with Anthropic: Claude Sonnet 4.6 ahead on 2 and Z.ai: GLM 5.1 ahead on 1.

Blended pricing is $6.00 per 1M tokens for Anthropic: Claude Sonnet 4.6 and $1.48 for Z.ai: GLM 5.1 — Z.ai: GLM 5.1 is about 4.0× cheaper.

Throughput is 44 tokens per second for Anthropic: Claude Sonnet 4.6 and 53 for Z.ai: GLM 5.1, with time to first token at 1.7s and 1.8s. Anthropic: Claude Sonnet 4.6 accepts 1.00M tokens of context against 205k.

Anthropic: Claude Sonnet 4.6 is proprietary; Z.ai: GLM 5.1 is proprietary. 23 tracked hosts serve one or both.

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

At a glance
MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Known Good Index 80 based on 4 of 7 evaluations 88 based on 3 of 7 evaluations
Blended $/1M $6.00 $1.48
Output tok/s 44 53
Context window 1.00M 205k
Providers 4 19
Jump to section

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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Known Good Index 80 88
Coding Index 71
Mathematics Index 86 92
Agentic Index 71 82
Openness Index 5 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Anthropic: Claude Sonnet 4.6 · marker = Z.ai: GLM 5.1 · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond87 / 85
Mock AIME 2024–2586 / 92
SWE-bench Verified75 / 74

Right-hand figures read Anthropic: Claude Sonnet 4.6 / Z.ai: GLM 5.1. Anthropic: Claude Sonnet 4.6 leads on 2 of 3, Z.ai: GLM 5.1 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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Text Arena 1,457 1,465
Text Arena (style controlled) 1,472 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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Input $/1M $3.00 $0.97
Output $/1M $15.00 $3.04
Blended $/1M $6.00 $1.48
Cache read $/1M $0.300 $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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Context window 1.00M 205k
Max output tokens 128k 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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Output tokens/s 44 53
Time to first token 1.7s 1.8s
The Known Good

Providers

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

23 hosts
Full provider benchmarks →
Provider Anthropic: Claude Sonnet 4.6 blendedAnthropic: Claude Sonnet 4.6 tok/s Z.ai: GLM 5.1 blendedZ.ai: GLM 5.1 tok/s
Google · first party $6.00 52
Anthropic · first party $6.00 38
Azure · first party $6.00 38
Amazon Bedrock · first party $6.00 36
CoreWeave $2.15 146
Wafer $1.55 87
GMICloud $1.50 66
Parasail $2.15 66
Venice $2.37 64
DeepInfra $1.66 62
Friendli $2.15 59
SiliconFlow $1.83 57
Crusoe $2.00 54
Novita $2.13 51
StreamLake $1.48 43
Baidu · first party $1.46 42
Phala $1.96 42
Z.AI · first party $2.15 42
Chutes $1.50 41
Nebius $2.15 29
AtlasCloud $1.94 27
DigitalOcean $1.81 20
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 →