# Xiaomi MiMo-V2-Flash (309B)

> Large MoE model that pushes sliding-window attention harder than most contemporaries.

| Property | Value |
| --- | --- |
| Lab | Xiaomi (China) |
| Released | 2025-12-16 |
| Decoder type | Sparse MoE |
| Family | Sparse MoE |
| Scale | 309B total, 15B active (4.9% active) |
| Context window | 262,144 tokens |
| Attention | 5:1 sliding-window/global attention |
| Layer mix | 40 sliding-window + 8 global |
| KV cache / token (bf16) | 144 KiB (Moderate) |
| License | MIT License |

**Key detail:** Uses an unusually small 128-token local window plus multi-token prediction.

## Architecture concepts

- [Sliding Window Attention (SWA)](https://llm-atlas-7or.pages.dev/concepts/swa.md): Some layers only attend to a local window of recent tokens instead of the whole context.
- [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 v4.3.2: total 16 (Scientific 4.3)

## Links

- Architecture diagram: https://sebastianraschka.com/llm-architecture-gallery/images/architectures/xiaomi-mimo-v2-flash-309b.webp
- View in article: https://magazine.sebastianraschka.com/p/the-big-llm-architecture-comparison#%C2%A719-xiaomi-mimo-v2-flash
- config.json: https://huggingface.co/XiaomiMiMo/MiMo-V2-Flash/blob/main/config.json
- Tech report: https://arxiv.org/pdf/2601.02780
- Source card (source of truth): https://sebastianraschka.com/llm-architecture-gallery/#card-xiaomi-mimo-v2-flash-309b
- Web page: https://llm-atlas-7or.pages.dev/models/xiaomi-mimo-v2-flash-309b/
- JSON: https://llm-atlas-7or.pages.dev/api/models/xiaomi-mimo-v2-flash-309b.json

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