---
title: "Safetensors Format (.safetensors) — ComfyUI Glossary & Node Definition"
description: "Hugging Face's zero-copy tensor serialization format that cannot execute arbitrary Python pickle code. Learn how Safetensors Format (.safetensors) works inside ComfyUI node workflows on Windows."
canonical: https://comfy.ink/words/safetensors
updated: 2026-10-17
---

# Safetensors Format (.safetensors)

Hugging Face's zero-copy tensor serialization format that cannot execute arbitrary Python pickle code.

## Facts (2026-10-17)

- **Term:** Safetensors Format (.safetensors)
- **In Short:** Hugging Face's zero-copy tensor serialization format that cannot execute arbitrary Python pickle code.
- **Applies To:** ComfyUI SD 1.5, SDXL, Flux & Video

## Definition: Safetensors Format (.safetensors)

Hugging Face's zero-copy tensor serialization format that cannot execute arbitrary Python pickle code.

ComfyUI defaults to .safetensors for checkpoints, LoRAs, VAEs, and ControlNets because they load faster via memory mapping on Windows and prevent malicious code execution.

## How to tune this in your ComfyUI workflow

Every parameter in ComfyUI is exposed directly on its node rather than hidden behind global settings tabs. You can inspect or override this behavior per pass in [ComfyUI Studio](https://comfy.ink/studio).

New to node graphs? Grab the Windows installer at [/download](https://comfy.ink/download) and open a built-in template from the workflow menu.

## FAQ

### What does Safetensors Format (.safetensors) do in ComfyUI?

Hugging Face's zero-copy tensor serialization format that cannot execute arbitrary Python pickle code. ComfyUI defaults to .safetensors for checkpoints, LoRAs, VAEs, and ControlNets because they load faster via memory mapping on Windows and prevent malicious code execution.

### Where do I adjust this setting on the canvas?

Check the corresponding loader or [KSampler](https://comfy.ink/nodes/ksampler) widget in your active workflow graph.

## Related

- [ComfyUI Glossary](https://comfy.ink/words)
- [KSampler & KSampler (Advanced)](https://comfy.ink/nodes/ksampler)
- [ComfyUI Studio Workspace](https://comfy.ink/studio)
- [ComfyUI VRAM Requirements for SDXL, Flux & Video (6GB–24GB)](https://comfy.ink/guides/comfyui-vram-requirements-guide)
- [Latent Space & LATENT Pin](https://comfy.ink/words/latent-space)

## Download

Free desktop app: [Download Comfy](https://comfy.ink/download)

Markdown mirror: https://comfy.ink/words/safetensors.md