How to validate domain name format?

In order to help your programming or testing tasks, FYIcenter.com has designed this online tool for you to validate any given domain name.

All you need to do is to enter a domain name and click the "Validate" button. Validation result will be displayed in the result area.

Validation result by FYIcenter.com - Domain Name:

Specified Domain Name: Valid ✔

Domain Name: sqa.fyicenter.com

What is a valid domain name?

A domain name is an identification of a unique computer system on the Internet. A complete domain name consists of one or more subdomain names and one top-level domain name separated by dots (.). For example, sqa.fyicenter.com is a complete domain name.

A complete domain name is valid if it meets the following criteria:

• A complete domain name must have one or more subdomain names and one top-level domain name.
• A complete domain name must use dots (.) to separate domain names.
• Domain names must use only alphanumeric characters and dashes (-).
• Domain names must not begin or end with dashes (-).
• Domain names must not have more than 63 characters.
• The top-level domain name must be one of the predefined top-level domain names, like (com), (org), or (ca)

The top-level domain name is validated using the IANA data file (as of April 1, 2023).

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