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Z.ai · Released August 2026

GLM-5.3

What it takes to run GLM-5.3 locally: memory by quantization, the GPUs that handle it, and how fast it runs.

Updated

Parameters
744B (40B active)
Architecture
Mixture of experts
Context
1.0M tokens
License
GLM-5.3 custom license
Memory at Q4_K_M
~466GB

What do you need to run GLM-5.3?

GLM-5.3 needs about 466GB of VRAM at Q4_K_M with 8K context (451GB for the weights plus KV cache and overhead). Because it is a mixture-of-experts model with 40B active parameters, it generates text much faster than a dense model of the same size, and it tolerates partial CPU offload better.

See the full hardware guide for GLM-5.3

What to buy

GPUs for GLM-5.3

Unified memory

M3 Ultra 512GB

512GB unified · $9,499 MSRP

Quant
Q3_K_M
Speed (est.)
~13 tok/s
Fits, tight

Speeds are estimates at the quantization shown with 8K context. We may earn a commission when you buy through these links. Learn more.

Memory

GLM-5.3 VRAM requirements by quantization

Lower-bit quantizations shrink the model at some cost to quality. Q4_K_M is the usual sweet spot. Totals include the KV cache for the context length shown plus runtime overhead.

Memory needed for GLM-5.3 at each quantization level
QuantizationQualityWeightsTotal @ 8K ctxTotal @ 32K ctx
Q2_KRough279 GB289 GB291 GB
Q3_K_MUsable363 GB375 GB377 GB
Q4_K_MRecommendedDefault451 GB466 GB468 GB
Q5_K_MVery good530 GB547 GB550 GB
Q6_KNear-lossless614 GB634 GB636 GB
Q8_0Practically lossless791 GB816 GB818 GB
BF16Full precision1,488 GB1,534 GB1,536 GB

KV cache note: Multi-head latent attention with DeepSeek-style sparse attention. Assuming the GLM-5 layout of 78 layers, each caching a 576-value latent (512 compressed plus 64 RoPE): 78 x 576 x 2 bytes = 89,856 bytes per token, about 94GB at 1M tokens, plus a small sparse-attention indexer cache. Layer count not confirmed from the config.

Performance

How fast GLM-5.3 runs

Single-user generation speed on popular GPUs that fit the model entirely in memory, at the best quantization each can hold.

  1. M5 Ultra 512GB

    Q3_K_M · 512GB

    ~19tok/s

  2. M3 Ultra 512GB

    Q3_K_M · 512GB

    ~13tok/s

Estimated (method)

Overview

About GLM-5.3

GLM-5.3 is Z.ai's flagship, released as open weights in August 2026, and it scores 44 on the Artificial Analysis Intelligence Index v4.3, level with Kimi K3 and among the highest of any open-weight model. It is a 744B mixture-of-experts with 40B active parameters, a 1M-token context, and a thinking mode, aimed at agentic coding and long-horizon tasks. At Q4_K_M it needs roughly 465GB with 8K context, so local use realistically means a 512GB Mac Studio or a multi-GPU server; the smallest community GGUFs start above 200GB. Unlike earlier GLM releases it uses a custom license with a revenue threshold, so check the terms before commercial use.

Strengths

  • +Among the strongest open-weight models for agentic coding and reasoning
  • +1M-token context
  • +Toggleable thinking mode

Weaknesses

  • −Needs roughly 465GB at Q4_K_M; even 1-bit to 2-bit builds exceed 200GB
  • −40B active parameters make it slow on unified-memory machines
  • −Custom license with a revenue threshold, unlike the MIT-licensed GLM-5.3-Flash
  • −Text only
CodingAgents & toolsReasoningWritingLong contextChatMathToggleable reasoning

Setup

How to run GLM-5.3

llama.cpp
$ llama-server -hf unsloth/GLM-5.3-GGUF:Q4_K_M -c 8192 -ngl 99

Weights: zai-org/GLM-5.3 · GGUF: unsloth/GLM-5.3-GGUF

Alternatives

Frequently asked questions

How much VRAM do you need to run GLM-5.3?

About 466GB at Q4_K_M with 8K tokens of context: 451.0GB of weights, 0.7GB of KV cache, and 14.1GB of runtime overhead. Higher-precision quants and longer contexts need more; see the table above.

Is GLM-5.3 free for commercial use?

GLM-5.3 is released under the GLM-5.3 custom license. Commercial use is allowed with some conditions; read the license before shipping a product.

How long a context does GLM-5.3 support?

Up to 1,048,576 tokens (1.0M). Long contexts need a lot of extra memory for the KV cache, so most local setups run 8K to 32K.

Sources: GLM-5.3 model card (Hugging Face), Unsloth: How to run GLM-5.3 locally, runaihome: GLM-5.3 open weights, license, and GGUF sizes. Capability score basis: Artificial Analysis Intelligence Index v4.3: 44 (September 2026), level with Kimi K3 and among the highest open-weight scores; the open frontier reference on the Llama Builds scale.