remove hostname and port from url using regular expression

You don't need any library or REGEX

var url = new URL('http://localhost:7001/www.facebook.com')
console.log(url.pathname)

https://developer.mozilla.org/en-US/docs/Web/API/URL

Based on @atiruz answer, but this is

url = url.replace( /^[a-zA-Z]{3,5}\:\/{2}[a-zA-Z0-9_.:-]+\//, '' );

• shortest
• can take https or ftp too
• can take url with or without explicit port