URL – all capitals. It’s an acronym for Uniform Resource Locator. HTML – when used in text to refer to the markup language, capitalize all the letters.
An Internet address is only case sensitive for everything after the domain name. For example, it does not matter if you use uppercase or lowercase with “computerhope.com,” it still reaches the same page. However, when typing the name of the page, file, or directory in the URL, it is case sensitive.
Answer: In any URL, caps are optional up to the .com part. Addresses are only case-sensitive after the .com (same goes for .org, .edu, and other types of URLs). However, if anyone types your domain in all lowercase, they’ll get there just fine.
There may be URLs, or parts of URLs, where case doesn’t matter, but identifying these may not be easy. Users should always consider that URLs are case-sensitive. Domain names are case insensitive according to RFC 4343. The rest of URL is sent to the server via the GET method.