JAVASCRIPT

regular expression for links

http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*(),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+

regex validate link

/^(?:http(s)?://)?[w.-]+(?:.[w.-]+)+[w-._~:/?#[]@!$&'()*+,;=.]+$/gm

link regex

var expression = /[-a-zA-Z0-9@:%._+~#=]{1,256}.[a-zA-Z0-9()]{1,6}([-a-zA-Z0-9()@:%_+.~#?&//=]*)?/gi;
var regex = new RegExp(expression);
var t = 'www.google.com';

if (t.match(regex)) {
  alert("Successful match");
} else {
  alert("No match");
}