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.
Do capital letters matter in a URL?
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.
Are WordPress URLs case sensitive?
Advanced users may be interested in knowing how URLs can be case insensitive even though Unix servers use a case-sensitive file system. The answer is that we use an Apache Web server module called mod_speling (sic), which “fixes” URL requests that don’t exactly match an existing file.
Is http case sensitive?
HTTP header names are case-insensitive, according to RFC 2616: Each header field consists of a name followed by a colon (“:”) and the field value. Field names are case-insensitive. (Field values may or may not be case-sensitive.)
Is FQDN case sensitive?
Host names (or ‘labels’), such as example.com are case-insensitive. DNS record types, such as ‘A’, and ‘MX’ are case sensitive. Values in TXT and SPF records are case sensitive.