# Cross-Layer KV Sharing (KV sharing)

> Later layers reuse key/value states produced by earlier layers.

Category: Efficiency & sharing

GQA shares KV heads across query heads within a layer; cross-layer sharing goes further and lets whole layers reuse another layer's keys and values, so fewer layers add to the cache.

Gemma 4 E2B and E4B are prominent examples of the idea from cross-layer attention research.

**Trade-off:** Smaller cache and less compute for long contexts, with less per-layer flexibility.

## Models using KV sharing (4)

- [Mistral Large 4 (1T)](https://llm-atlas-7or.pages.dev/models/mistral-large-4.md) — Mistral AI, 2026-10-29
- [DeepSeek V4.1-Flash (552B)](https://llm-atlas-7or.pages.dev/models/deepseek-v4-1-flash.md) — DeepSeek, 2026-09-10
- [Gemma 4 (E2B)](https://llm-atlas-7or.pages.dev/models/gemma-4-e2b.md) — Google, 2026-04-02
- [Gemma 4 (E4B)](https://llm-atlas-7or.pages.dev/models/gemma-4-e4b.md) — Google, 2026-04-02

Full explainer with figures by Sebastian Raschka: https://sebastianraschka.com/llm-architecture-gallery/kv-sharing/
Web page: https://llm-atlas-7or.pages.dev/concepts/kv-sharing/