# Grok 2.5 (270B)

> Rare production-model release that shows an older MoE style with fewer, larger experts.

| Property | Value |
| --- | --- |
| Lab | xAI (United States) |
| Released | 2025-08-22 |
| Decoder type | Sparse MoE |
| Family | Sparse MoE |
| Scale | 270B parameters |
| Context window | 131,072 tokens |
| Attention | GQA |
| Layer mix | 64 GQA |
| KV cache / token (bf16) | 256 KiB (High) |
| License | Grok 2 Community License Agreement |

**Key detail:** Adds an always-on SwiGLU path that effectively behaves like a shared expert.

## Architecture concepts

- [Grouped-Query Attention (GQA)](https://llm-atlas-7or.pages.dev/concepts/gqa.md): Several query heads share one key/value head, shrinking the KV cache with little quality loss.
- [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.

## Links

- Architecture diagram: https://sebastianraschka.com/llm-architecture-gallery/images/architectures/grok-2-5-270b.webp
- View in article: https://magazine.sebastianraschka.com/p/the-big-llm-architecture-comparison#%C2%A710-grok-25
- config.json: https://huggingface.co/xai-org/grok-2/blob/main/config.json
- Source card (source of truth): https://sebastianraschka.com/llm-architecture-gallery/#card-grok-2-5-270b
- Web page: https://llm-atlas-7or.pages.dev/models/grok-2-5-270b/
- JSON: https://llm-atlas-7or.pages.dev/api/models/grok-2-5-270b.json

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