Guide
Using example.com, example.org and example.net
The reserved example domains are the internet's placeholder text: safe, universal stand-ins you can paste into docs, tests and tutorials without ever touching a real website. Here is what they are, how to use them well, and when to reach for something more.
What the reserved domains are
In 1999, the IETF set aside a small set of names so that
documentation could be written without accidentally pointing at a
real, owned website. That reservation lives in
RFC 2606 and was later extended by
RFC 6761. The Internet Assigned Numbers Authority
(IANA) keeps the list, which includes
example.com, example.net,
example.org, the bare example TLD, and
the special-use names .test, .invalid
and .localhost.
The practical point is simple: these names are reserved, not registered. No one can buy them, so an example in your README can never silently resolve to someone else's production site or leak traffic to a domain squatter. They are a guaranteed blank canvas.
Because all three behave the same way, examples stay portable
across example.com, example.org and
example.net. Pick whichever reads best for your
audience — a nonprofit tutorial might prefer
example.org, a product doc might prefer
example.com — and switch freely without rewriting the
lesson. The reserved TLDs are also locale-neutral: the same
example works whether your docs are in English, Spanish or
Japanese.
Rules of safe use
Reserved domains are safe to write about. They are not a service you can depend on. Keep these rules in mind:
-
Don't rely on them as a live service. They aren't an API, a CDN or a hosting platform. Treat any response you happen to get as a courtesy, not a contract.
-
Don't build tests or monitoring on their content. Asserting on the HTML, status codes or response times of example domains will produce brittle, failing checks the moment anything changes upstream.
-
Don't ship production apps against them. No real business logic, no user data and no billing should ever route through a name you don't control.
-
Never authenticate or send secrets. There is no account behind these domains. Posting credentials, tokens or personal data to them is both pointless and risky.
None of this makes them dangerous — it just means they're placeholders. Use them to illustrate, not to operate.
When to graduate
The moment you need an example to actually respond with data, you've outgrown a static placeholder. The Example Hub directory maps each need to a purpose-built, fake-data tool:
Fake REST / JSON APIs
Need structured records to fetch? Use a mock JSON API that returns realistic, disposable data.
HTTP echo / debugging
Inspect headers, methods and payloads? Use an HTTP echo service that reflects your request back.
Mock images
Filling a layout with pictures? Use placeholder-image services with any size or label you like.
Custom responses
Need exact status codes, delays or bodies? Stand up or point at a configurable mock server.
Consistent with the safe-use rules above: even these tools are for development and demos, never for production data.
Why this page is fast and private
This page is deliberately boring under the hood, in the best way:
- No trackers or analytics. Nothing here phones home, sets a cookie or profiles you.
- No external fonts or JavaScript. The page uses the system font stack and ships no third-party requests, so it loads instantly and offline-friendly.
- Works with JavaScript disabled. The content, navigation and links are plain HTML and function without scripts.
- Dark-mode aware and WCAG-AA. Colors follow your OS theme and meet accessible contrast ratios in both light and dark.
Fast, private and dependable by default — the same promise the reserved example domains make to your documentation.
Learn more / references
The authoritative source is IANA's own short help page, with the specifications close behind:
- IANA — Example Domains The official explanation of the reserved names.
- RFC 2606 — Reserved Top Level DNS Names The original 1999 reservation of example/test/invalid/localhost.
- RFC 6761 — Special-Use Domain Names Extends the reserved set and defines how resolvers treat it.
Looking for hands-on tools instead of theory? Return to the Example Hub directory.