---
title: "Example domains: reserved names vs look-alikes"
description: "Which names are reserved for documentation (RFC 2606, RFC 6761), why look-alikes such as example-petstore.com get real traffic, and what to use."
url: https://example-petstore.com/example-domains
language: en
---

# Example domains

Documentation needs addresses that look real but lead nowhere. Some names are reserved for exactly that. Others, such as example-petstore.com, only look like examples: they are ordinary registered domains, and whatever is sent to them reaches a real server.

## Reserved names

Two standards reserve names for documentation and testing:

- **RFC 2606 (1999)** reserves the second-level domains `example.com`, `example.net` and `example.org`, and the top-level domains `.test`, `.example`, `.invalid` and `.localhost`.
- **RFC 6761 (2013)** sets out how software and DNS should treat these special-use names.

IANA runs a simple page on `example.com` and states that the example domains may be used in documents without asking permission. It expects some traffic from incorrectly configured applications and asks developers not to build anything that depends on it.

## Registered look-alikes

Names like example-petstore.com, example-commerce-host.com or my-example-blog.com contain the word “example”, but they are not reserved. Anyone can register them, and then every link, form, tracking call or API request that uses them reaches that owner, including any credentials inside. Research on look-alike domains shows how much this can be: a 2017 study estimated that about 1,200 typo domains of e-mail providers receive around 800,000 misdirected e-mails a year.

Google used example-petstore.com and example-commerce-host.com in its Analytics and Search documentation from 2009 on. [The history](https://example-petstore.com/history) lists where and when.

## Which names to use

| You need | Use | Avoid |
| --- | --- | --- |
| A website | `www.example.com` | made-up names such as `example-petstore.com` or `mysite.com` |
| A second domain (cart, checkout, partner) | `example.net` or `example.org` | `example-commerce-host.com`, `example-b.com` |
| Subdomains | `shop.example.com`, `api.example.com` | `api.example-petstore.com` |
| An internal or test host | `app.test`, `db.example` | real-looking names under `.com` or `.io` |
| An address that must never resolve | `anything.invalid` | — |
| An email address | `user@example.com` | addresses on registered domains |

## What this domain does

example-petstore.com and example-commerce-host.com show an explanation on every address, answer API requests with `410 Gone` and a JSON explanation, and point visitors to [step-by-step guides](https://example-petstore.com/guides) for removing the names from their sites and code.

More reserved values, such as IP addresses, phone numbers and test cards: [Example values that are safe to use](https://example-petstore.com/guides/example-values)

## Related guides

### [The history of example-petstore.com](https://example-petstore.com/history)

When and where Google used example-petstore.com and example-commerce-host.com, from 2009 to today, with archived sources.

### [Glossary](https://example-petstore.com/glossary)

Short explanations of `_setDomainName`, linker, `_gl`, unwanted referrals, SearchAction and 410 Gone.

### [Example values that are safe to use](https://example-petstore.com/guides/example-values)

Reserved domains, IP ranges, AS numbers, MAC addresses, phone numbers and test cards for examples that stay harmless.

## Sources

- [RFC 2606: Reserved Top Level DNS Names](https://www.rfc-editor.org/rfc/rfc2606) IETF
- [RFC 6761: Special-Use Domain Names](https://www.rfc-editor.org/rfc/rfc6761.html) IETF
- [Example Domains](https://www.iana.org/help/example-domains) IANA
- [IANA-managed Reserved Domains](https://www.iana.org/domains/reserved) IANA
- [Email Typosquatting (Szurdi and Christin, IMC 2017)](https://conferences.sigcomm.org/imc/2017/papers/imc17-final215.pdf) ACM Internet Measurement Conference