# GLM-5.3-Flash (320B)

> Natively multimodal GLM refresh, previously previewed as Ox Alpha, that replaces most MLA/DSA layers with Kimi Delta Attention and adds four-stream mHC.

| Property | Value |
| --- | --- |
| Lab | Z.ai (China) |
| Released | 2026-08-26 |
| Decoder type | Sparse hybrid |
| Family | Hybrid MoE |
| Scale | 320B total, 18B active (5.6% active) |
| Context window | 1,048,576 tokens |
| Attention | 3:1 Kimi Delta Attention and MLA with DeepSeek Sparse Attention |
| Layer mix | 34 KDA + 11 MLA/DSA + 1 MTP layer |
| KV cache / token (bf16) | 11 KiB (Very low) |
| License | MIT License |

**Key detail:** Mixes 34 Kimi Delta Attention layers with 11 MLA/DSA layers and routes residuals through four mHC streams.

## Architecture concepts

- [Hybrid Attention (Hybrid attention)](https://llm-atlas-7or.pages.dev/concepts/hybrid-attention.md): Mixes cheap linear-attention or state-space layers with a few full-attention layers.
- [Short Convolution (ShortConv)](https://llm-atlas-7or.pages.dev/concepts/shortconv.md): A tiny causal depthwise convolution (kernel ≈ 4) that mixes each channel over the last few tokens.
- [Multi-Head Latent Attention (MLA)](https://llm-atlas-7or.pages.dev/concepts/mla.md): Keys and values are compressed into a small latent vector that is cached instead of full K/V.
- [DeepSeek Sparse Attention (DSA)](https://llm-atlas-7or.pages.dev/concepts/deepseek-sparse-attention.md): A lightweight indexer scores past tokens and each query attends only to its top-k picks.
- [No Positional Embeddings (NoPE)](https://llm-atlas-7or.pages.dev/concepts/nope.md): Some or all layers drop explicit positional encodings and rely on the causal mask.
- [Manifold-constrained Hyper-Connections (mHC)](https://llm-atlas-7or.pages.dev/concepts/mhc.md): Several parallel residual streams with learned, constrained mixing between them.
- [Mixture of Experts (MoE)](https://llm-atlas-7or.pages.dev/concepts/moe.md): Many feed-forward experts, but a router sends each token to only a few of them.
- [Multi-Token Prediction (MTP)](https://llm-atlas-7or.pages.dev/concepts/mtp.md): Extra heads learn to predict several future tokens, and can draft tokens at inference.

## Benchmark (Artificial Analysis Intelligence Index)

- AA Intelligence Index v5.0: total 27.8 (Knowledge Work 43.7, Coding 23.7, Science 12.5, General 30.9)
- AA Intelligence Index v4.3.2: total 41.8 (General 39.7, Scientific 27.6, Coding 42.2, Agents 53)

## Links

- Architecture diagram: https://sebastianraschka.com/llm-architecture-gallery/images/architectures/glm-5.3-flash.webp
- config.json: https://huggingface.co/zai-org/GLM-5.3-Flash/blob/main/config.json
- License: https://huggingface.co/zai-org/GLM-5.3-Flash/blob/main/LICENSE
- Tech report: https://arxiv.org/pdf/2602.15763
- Source card (source of truth): https://sebastianraschka.com/llm-architecture-gallery/#card-glm-5-3-flash
- Web page: https://llm-atlas-7or.pages.dev/models/glm-5-3-flash/
- JSON: https://llm-atlas-7or.pages.dev/api/models/glm-5-3-flash.json

_Data from Sebastian Raschka's LLM Architecture Gallery (https://sebastianraschka.com/llm-architecture-gallery/). Synced 2026-11-04._