A big mapping url schemes to their protocols' default ports. See comments below for notes. Painstakingly assembled by crossreferencing https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml and https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml

scheme_port_map.json

{
  "acap": 674, 
  "afp": 548, 
  "dict": 2628, 
  "dns": 53, 
  "file": null, 
  "ftp": 21, 
  "git": 9418, 
  "gopher": 70, 
  "http": 80, 
  "https": 443, 
  "imap": 143, 
  "ipp": 631, 
  "ipps": 631, 
  "irc": 194, 
  "ircs": 6697, 
  "ldap": 389, 
  "ldaps": 636, 
  "mms": 1755, 
  "msrp": 2855, 
  "msrps": null, 
  "mtqp": 1038, 
  "nfs": 111, 
  "nntp": 119, 
  "nntps": 563, 
  "pop": 110, 
  "prospero": 1525, 
  "redis": 6379, 
  "rsync": 873, 
  "rtsp": 554, 
  "rtsps": 322, 
  "rtspu": 5005, 
  "sftp": 22, 
  "smb": 445, 
  "snmp": 161, 
  "ssh": 22, 
  "steam": null, 
  "svn": 3690, 
  "telnet": 23, 
  "ventrilo": 3784, 
  "vnc": 5900, 
  "wais": 210, 
  "ws": 80, 
  "wss": 443, 
  "xmpp": null
}

schemes_without_netloc.json

[
  "mailto", 
  "about", 
  "sip", 
  "tel", 
  "data", 
  "urn", 
  "bitcoin", 
  "pkcs11", 
  "magnet", 
  "blob", 
  "sips", 
  "news", 
  "geo"
]

A null in the scheme_port_map indicates a protocol that uses a "//" but does not use a (known) port.

The schemes_without_netloc.json file is a short list of common URL schemes that affirmatively do not use network location (no // in the URL).

Note that the list is hand assembled, and not automatically generatable, as the name in the IANA scheme registry does not always map well to the IANA port registry. So this made mostly by hand looking up in the port registry, or the linked RFC. Some schemes do not have RFCs linked, and some RFCs do not mention the default port, so some independent research was also necessary.

Anyways, hope I saved someone else the trouble! (Python versions of the above can be imported from boltons's urlutils submodule).

Hi,
nice list! If you want others to benefit from this, it would be helpful though if you add some kind of license or explicitly release it into public domain.

@pgroke-dt, just seeing this, and while I think this might be too small an artifact to be copyrightable per se (facts are not copyrightable), if it eases anyone's concerns further, I'm happy to say that the contents of this gist are licensed CC0.

Also, in addition to boltons, the mapping is available in hyperlink as well. :)

Yes, you're probably right re. being non copyrightable. I think your comment here should be enough in case anyone has concerns. Thanks :)