Question

Situation:

I got one input field and it needs to check if the input value is a regular string or a URL (link to a website).

What’s the best way to check this?

Answer 1

Try this regex

[-a-zA-Z0-9@:%_\+.~#?&//=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?&//=]*)?

from
http://gskinner.com/RegExr/?2rj36

Sample usage

var reg  = /[-a-zA-Z0-9@:%_\+.~#?&//=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?&//=]*)?/;

alert(reg.test("hello"));
alert(reg.test("www.hello.com"));
alert(reg.test("http://hello.com"));
alert(reg.test("http://www.hello.com"));