Production model
GLM-4.5
Architecture
| Positional encoding | RoPE (theta 1e6; partial rotary factor 0.5) |
|---|---|
| Norm placement | Pre-Norm |
| Norm type | RMSNorm |
| QK-Norm | yes |
| Activation | SwiGLU (SiLU) |
| Attention | GQA (96 query heads, 8 KV heads) |
| MoE | Sparse MoE — 160 routed experts, top-8 routing, 1 shared expert; routed_scaling_factor 2.5 |
| Other | 92 layers, hidden dim 5120, expert intermediate dim 1536, Depth-over-width: 92 layers with hidden dim 5120 (vs ~64 layers at hidden 7K for similar-active-param models), Multi-Token Prediction (MTP) head, Muon optimizer for training, MIT license |
Techniques used
- Grouped-Query Attention — 96 query heads over 8 KV heads (G = 12) — a high-Q / aggressive-GQA configuration.
- DeepSeekMoE — 160 routed experts + 1 shared expert per MoE layer; top-8 routing; the shared-expert pattern carried over from the DeepSeek-MoE line.
- Swish-Gated Linear Unit — SwiGLU (SiLU activation per the released config.json) inside each expert.
- Query-Key Normalization — QK-Norm called out as one of the explicit architectural choices alongside GQA, MTP, and the Muon optimizer.
- Root Mean Square Layer Normalization — RMSNorm with rms_norm_eps 1e-5 in the released config; 92 transformer layers.
- Rotary Position Embedding — RoPE with theta = 10⁶ and a partial rotary factor of 0.5 — half the head dim carries rotation.
GLM-4.5 (July 2025) is Zhipu AI’s open-weights MoE flagship — 355B total parameters, 32B
active per token, 92 transformer layers. The technical report (arXiv:2508.06471) and the
released config.json together document a Pre-Norm RMSNorm + RoPE + GQA + SwiGLU
- MoE stack with two notable choices:
- Depth over width. 92 layers at hidden dim 5120 (vs the more common ~60–65 layers at hidden dim 7K–8K for similar active-parameter MoEs). The report frames the choice as a bet that depth improves reasoning at fixed active-param budget.
- 96 attention heads, 8 KV heads. A high query-head count — large query bandwidth per layer — combined with aggressive GQA sharing (G = 12).
- QK-Norm in attention, plus Multi-Token Prediction (MTP) head for speculative decoding, and Muon as the pre-training optimizer.
The MoE is sized at 160 routed experts plus one always-on shared expert, top-8 routing, expert intermediate dim 1536. This puts the routing density (8 + 1 active per token) in between DeepSeek V3 (8 + 1 of 256 + 1) and Qwen3 235B (8 of 128, no shared expert).
A companion model, GLM-4.5-Air, uses the same architectural recipe at 106B total / 12B active for lower-cost deployment. Both ship under the MIT license.
Context handling at 128K uses RoPE with theta = 10⁶ and a partial rotary factor of 0.5 — half the head dim carries rotary position information, the other half is plain.
For Zhipu’s earlier dense entry see GLM-4 9B and the 2022 baseline GLM 130B.
Sources
- https://arxiv.org/abs/2508.06471
- https://huggingface.co/zai-org/GLM-4.5
- https://huggingface.co/zai-org/GLM-4.5/blob/main/config.json
Export
BibTeX
@article{arxiv_2508_06471,
title = {GLM-4.5},
author = {Zhipu AI},
year = {2025},
eprint = {2508.06471},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2508.06471}
} CSL JSON
{
"id": "arxiv_2508_06471",
"type": "article-journal",
"title": "GLM-4.5",
"author": [
{
"literal": "Zhipu AI"
}
],
"issued": {
"date-parts": [
[
2025
]
]
},
"URL": "https://arxiv.org/abs/2508.06471",
"number": "2508.06471",
"source": "arXiv"
} RIS
TY - JOUR
TI - GLM-4.5
AU - Zhipu AI
PY - 2025
JO - arXiv
AN - arXiv:2508.06471
UR - https://arxiv.org/abs/2508.06471
ER - Models like this
- Hunyuan-Large 389BTencent83% overlap
- Qwen3 30B-A3BAlibaba (Qwen Team)71% overlap
- Qwen3 32BAlibaba (Qwen Team)71% overlap