GLM-5.3-Flash

Organization
Z.ai / THUDM
Parameters
320B total / 18B active
Context
1M
License
MIT
Release
2026-08-25

MoE, 45 layers + 1 MTP, 288 experts + 1 shared, top-8, KDA linear-attn + sparse MLA

GLM-5.3-Flash is Z.ai's 320B-total / 18B-active MoE with KDA linear attention and sparse MLA, shipping a 1M-token context under the MIT license. Its quantization story centers on the nvidia NVFP4 checkpoint, which holds BF16 quality on a GB200 (GPQA Diamond 92.17 → 92.11) while the turboderp EXL3 build at 2.05 bpw (85.2 GB) reaches 41.8 tok/s on two RTX Pro 6000 cards.

GLM-5.3-Flash is a 320B total / 18B active MIT model from Z.ai / THUDM with 1M context. Quantized checkpoints lose 0.06–0.76 points on the 3 measured per-quant benchmarks.

Base-model benchmarks

Terminal-Bench 2.1

84.3

DeepSWE v1.1

63.4

HLE w/ tools

55.3

ALE-CLI

26.3

GPQA Diamond (BF16)

92.17

SciCode (BF16)

56.21

MMMU-Pro (BF16)

76.88

IFBench (BF16)

61.3

Terminal-Bench 2.1 (BF16)

82.58

Quant checkpoints

CheckpointFamilySizeSource
zai-org FP8 native

~306 GiB official checkpoint

FP8306 GBsource ↗
amd GLM-5.3-Flash-Quark-MXFP4MXFP4185 GBsource ↗
OneNexus GLM-5.3-Flash-MXFP4MXFP4195.6 GBsource ↗
nvidia GLM-5.3-Flash-NVFP4

Size not captured

NVFP4—source ↗
unsloth GLM-5.3-Flash-GGUF UD-Q2_K_XL

~109 GB

GGUF109 GBsource ↗
unsloth GLM-5.3-Flash-GGUF Q3_K_XLGGUF137.4 GBsource ↗
unsloth GLM-5.3-Flash-GGUF Q4_K_XLGGUF185.99 GBsource ↗
ggml-org GLM-5.3-Flash Q4_KGGUF168.92 GBsource ↗
turboderp GLM-5.3-Flash EXL3 2.05bpwEXL385.2 GBsource ↗
autotrust GLM5.3-Flash-E256-DGX-Spark NVFP4

NVFP4 E256 expert-pruned

NVFP4170.5 GBsource ↗
autotrust GLM5.3-Flash-E224-DGX-Spark NVFP4

NVFP4 E224 expert-pruned

NVFP4151.5 GBsource ↗
canada-quant GLM-5.3-Flash-W4A16-MTP

W4A16-MTP

GGUF177.7 GBsource ↗
AxonZeta GLM-5.3-Flash-AZ-Focus-EXL3

EXL3 AZ-Focus; size not captured

EXL3—source ↗

Per-quant quality deltas

nvidia NVFP4 (BF16→NVFP4, GB200)

source ↗

GPQA Diamond

92.11−0.06

baseline 92.17

SciCode

57.69+1.48

baseline 56.21

MMMU-Pro

76.3−0.58

baseline 76.88

IFBench

60.54−0.76

baseline 61.3

Terminal-Bench 2.1

83.15+0.57

baseline 82.58

NVFP4 E256 expert-pruned (autotrust)

source ↗

HumanEval

97.6

GPQA Diamond

77.3

C-Eval

89.4

AIME 2025

74.2

MMMU

76.1

NVFP4 E224 expert-pruned (autotrust)

source ↗

GPQA Diamond

90.9

AIME 2025

88.3

HumanEval

98.2

C-Eval

84

MMMU

73.6

W4A16-MTP (canada-quant)

source ↗

AIME 2025

88.33

GSM8K

97

GPQA Diamond

85.86

MMMU

74.67

EXL3 AZ-Focus (AxonZeta)

source ↗

MMLU-Pro

86.8+0.6

baseline 86.2

AIME 2025

81.7+6.7

baseline 75

GPQA Diamond

82.3+1.5

baseline 80.8

HumanEval+

86.9+1.1

baseline 85.8

Serving metrics

KV pool @128K (FP8 vs BF16)

14.92 M tokens (vs 8.87M BF16)

Hardware: AMD MI355X

Setup: vLLM FP8 TP4

source ↗

KV capacity

1.8 x (SGLang FP8 KV, +2.9–5.7% throughput)

Hardware: NVIDIA GB300

Setup: SGLang FP8 KV cache

source ↗

EXL3 decode

41.8 tok/s

Hardware: 2x NVIDIA RTX Pro 6000

Setup: turboderp EXL3 2.05bpw (TabbyAPI)

source ↗

FP8 single-tray fit

1 GB200 tray (vLLM FP8 TP4 + MTP5)

Hardware: NVIDIA GB200

Setup: vLLM FP8 TP4 + MTP5

source ↗

What’s not published

  • The official full benchmark table is image-only on the model card.
  • No per-quant quality table is published for the MXFP4 and GGUF checkpoints — the autotrust, canada-quant and AxonZeta cards publish single-score or paired tables only.

Sources

FAQ

What is GLM-5.3-Flash's license, context window and parameter count?
MIT license, 1M context window, 320B total / 18B active parameters (Z.ai / THUDM).
How much quality does quantization cost GLM-5.3-Flash?
Across 9 published deltas, quantized checkpoints differ from the full-precision baseline by 1.17 points on average (range -0.76 to 6.7).
How many quant checkpoints are cataloged for GLM-5.3-Flash?
13 checkpoints across FP8, MXFP4, NVFP4, GGUF, EXL3, sizes from 85.2 GB to 306 GB.
When was GLM-5.3-Flash released?
2026-08-25.
Where do the GLM-5.3-Flash benchmark numbers come from?
From 12 official sources — vendor model cards, quantization publisher cards and serving recipe pages.

Compare with

All numbers are measured benchmarks published by the model vendor or the quantization provider.