Ask HN: What Is the Cardinality of URLs?

I wonder what the total number of valid URLs including protocol, hostname, path, query parameters, etc. is. A sort of Drake Equation for URLs. This came up when wondering what the cardinality of a single repo on github.com is.

I assume it's more complex than [number of valid characters]^[browser character limit]. Networking equipment, browsers, archaic protocols, etc. all place limitations/requirements on this number.

Feel free to simplify it (ex: a single domain) or make it more complex as necessary. For consistency's sake let's assume I use Chromium stable on 2024-01-01 00:00:01 UTC and the request actually goes out onto the internet (so other hardware touches it)