---
id: "onion"
kind: "glossary-term"
title: ".onion"
language: "en"
category: "Alternative naming systems"
updated: "2026-10-04T14:01:23Z"
canonical: "https://tldlog.com/glossary/onion/"
translations:
  es: "https://tldlog.com/es/glosario/onion/"
  de: "https://tldlog.com/de/glossar/onion/"
  fr: "https://tldlog.com/fr/glossaire/onion/"
  it: "https://tldlog.com/it/glossario/onion/"
  pt-BR: "https://tldlog.com/pt/glossario/onion/"
  ru: "https://tldlog.com/ru/glossariy/onion/"
  zh-Hans: "https://tldlog.com/zh/cihui/onion/"
---

# .onion

The ending used for services inside the Tor network, which hides where a service is hosted. The IETF reserved it as a special-use name in 2015, so it is never looked up in the DNS and is not part of the DNS root. Only Tor software can reach these addresses.

## related terms

- [.alt](https://tldlog.com/glossary/alt-tld/)
- [namespace](https://tldlog.com/glossary/namespace/)
- [root zone](https://tldlog.com/glossary/root-zone/)
- [name collision](https://tldlog.com/glossary/name-collision/)
- [IETF](https://tldlog.com/glossary/ietf/)