Test Addresses on Reserved Domains
Create test address strings using reserved example or testing domains. These values can fill a sample dataset without inserting real third-party domains. The generator does not contact a mail service or provision an inbox. Reach for it when you need a mockup filled in, a documentation example written or a form layout checked in a controlled environment. If your test actually sends messages, configure the test mail transport separately: an address string alone does not isolate delivery or provide a receiving mailbox.
Which Domain to Pick, and What Each Is For
| Domain choice | Example address string | Scope |
|---|---|---|
| example.com, example.net, example.org | useruser00@example.com | Documentation examples; not an inbox from this tool |
| mail.invalid | testuser@mail.invalid | Reserved invalid-domain namespace |
| mail.test | demouser@mail.test | Reserved testing namespace; a local test setup may configure it |
The addresses illustrate possible strings. They do not identify created accounts.
Choosing Domain, Batch Size and Base
- Choose a reserved domain and a batch of 1, 5, 10, 15 or 20 addresses.
- Choose a character base or two-word base.
- Set base length for character modes, or a separator for two-word mode. Decide whether to append two digits.
- Generate, inspect and copy the list or an individual address.
Two words plus an underscore and a suffix can produce user_test00; choosing Letters base still appends digits when that checkbox is enabled.
How the Strings Are Randomized
Web Crypto supplies random values to rejection sampling for character, length, word and suffix choices. There is no Math.random fallback; failure clears the batch and shows an error. Two-word mode draws from a fixed 40-word list, so it has fewer combinations than a large vocabulary and can repeat values. Neither random mode nor an added suffix guarantees uniqueness.
Changing a setting clears the previous batch so displayed addresses always match the settings that generated them. Addresses are generated in your browser without contacting a mail service.
Why a Realistic Shape Proves Nothing
A plausible email shape does not prove deliverability or satisfy account verification. Real domains with names such as test.com are not reserved example domains. Word separators and base length affect different modes, as shown by the disabled controls. Turning off the suffix does not remove digits from Digits base or Letters and digits base.
Use example domains for public documentation and your configured test namespace for controlled integrations. If a database requires unique addresses, check and deduplicate the generated list. Copy failures leave the output selectable; changing settings or regenerating clears stale success feedback.
References: IANA example domains, RFC 2606 and IANA special-use domain registry.