The Known Good Updated 25 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 61
80based on 4 of 6 evaluations
Known Good Index
Speed
#197 of 316
41.2
Output tokens per second
Price
#301 of 340
$6.00
Blended per 1M tokens
In $3.00 · Out $15.00
Cache hit price
#165 of 206
$0.30
per 1M tokens (−90%)
Context
#55 of 345
1.00M
tokens (~1,500 pages)
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)
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 41 tokens per second for Anthropic: Claude Sonnet 4.6 and 53 for Z.ai: GLM 5.1, with time to first token at 1.6s and 1.9s. 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 25 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 6 evaluations 88 based on 3 of 6 evaluations
Blended $/1M $6.00 $1.48
Output tok/s 41 53
Context window 1.00M 205k
Providers 4 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.

MetricAnthropic: Claude Sonnet 4.6Z.ai: GLM 5.1
Known Good Index 80 88
Coding Index 71
Mathematics Index 86 92
Science Index 91 89
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
MATH / AIME86 / 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 1,458 1,465
Text Arena (style controlled) 1,473 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.

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 41 53
Time to first token 1.6s 1.9s
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
Amazon Bedrock · first party $6.00 41
Google · first party $6.00 41
Anthropic · first party $6.00 38
Azure · first party $6.00
CoreWeave $2.15 120
Friendli $2.15 109
Crusoe $2.00 91
Fireworks $2.15 90
Venice $2.37 80
GMICloud $1.50 77
Parasail $2.15 71
DeepInfra $1.66 66
SiliconFlow $1.83 62
Novita $2.13 52
Baidu · first party $1.50 51
Wafer $1.55 50
Chutes $1.50 48
AtlasCloud $1.94 42
Z.AI · first party $2.15 37
Nebius $2.15 26
StreamLake $1.48 25
DigitalOcean $1.81 21
Phala $1.96

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 →