example-petstore.com

Example domain · Not a live service · Browser visits show this page · API requests get 410 Gone

Guide · Documentation

Example values that are safe to use

Documentation, tutorials and tests need addresses, numbers and names that look real but never reach anyone. For most kinds of value a reserved range exists. This guide lists them, with the source for each, so examples stay harmless when someone copies them.

Why reserved values

Examples get copied: into code, configuration files, tests and other documentation. A value that looks invented but belongs to someone sends that traffic, those e-mails or those calls to a real party. example-petstore.com is a case in point: an invented name in Google’s documentation that anyone could register, and that still receives requests. Reserved values are guaranteed never to be assigned, so a copied example fails harmlessly.

Domain names and e-mail

For websites, APIs and e-mail addresses in examples, use example.com, example.net or example.org and their subdomains, such as api.example.com and user@example.com. For test environments, names that must never resolve and local networks there are .test, .invalid, .localhost, home.arpa and .internal.

What each reserved name is for, and why look-alikes such as example-petstore.com are not safe: Example domains

IP addresses

TypeReserved for documentationSource
IPv4192.0.2.0/24 (TEST-NET-1), 198.51.100.0/24 (TEST-NET-2), 203.0.113.0/24 (TEST-NET-3)RFC 5737
IPv62001:db8::/32RFC 3849
IPv6, larger networks3fff::/20RFC 9637 (2024)
 
# A client, a server and a proxy in an example
client   192.0.2.10        2001:db8::10
server   198.51.100.20     2001:db8:1::20
proxy    203.0.113.30      2001:db8:2::30

The three IPv4 blocks give an example three separate “networks”, which helps when explaining routing or firewalls. 3fff::/20 exists because 2001:db8::/32 is too small to show realistic allocations for large providers.

AS numbers

For BGP examples: 64496–64511 (16-bit) and 65536–65551 (32-bit), reserved for documentation by RFC 5398. Private-use AS numbers are meant for real networks, not for examples.

MAC addresses

00-00-5E-00-53-00 to 00-00-5E-00-53-FF (written as 00:00:5e:00:53:00 in most tools) are reserved for documentation by RFC 9542 (which replaced RFC 7042).

Phone numbers

There is no worldwide range; several countries reserve their own for fiction and examples:

  • United States and Canada: 555-0100 to 555-0199, with any area code, such as +1 202 555 0143.
  • United Kingdom (Ofcom): mobile 07700 900000 to 07700 900999, London 020 7946 0000 to 020 7946 0999, and 01632 960000 to 01632 960999 without a specific area.

For other countries, check the telecom regulator. Where no range exists, use a placeholder that cannot be dialled, such as +31 6 XXXX XXXX, rather than digits that merely look random.

Payment cards

Payment providers publish test card numbers that only work in their test mode, such as Stripe’s 4242 4242 4242 4242 with any future expiry date and any CVC. Use the numbers of the provider you are integrating with; test numbers from one provider are not accepted by another. Never use a real card number, not even your own, in documentation, fixtures or screenshots.

What not to use

  • Invented look-alike domains such as example-petstore.com, mycompany.com or test.com: they can be, and often are, registered.
  • Private address ranges such as 10.0.0.0/8 or 192.168.0.0/16 in public documentation: they exist in the reader’s own network, so a copied example may reach a real device there.
  • Real-looking API keys: write a clear placeholder such as YOUR_API_KEY or sk_test_…, never a key that was ever valid.
  • Real people’s data: names, e-mail addresses and phone numbers of colleagues or customers do not belong in examples or test fixtures.

Sources