// NOTE: http:// or https:// are required here in the beginning of the link

// parse

function isValidHttpUrl(string) {

  let url;

  try {

    url = new URL(string);

  } catch (_) {

    return false;  

  }

​

  return url.protocol === "http:" || url.protocol === "https:";

}

​

// or regexp

function validURL(str) {

  var pattern = new RegExp('^(https?:\\/\\/)?'+ // protocol

    '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name

    '((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address

    '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*'+ // port and path

    '(\\?[;&a-z\\d%_.~+=-]*)?'+ // query string

    '(\\#[-a-z\\d_]*)?$','i'); // fragment locator

  return !!pattern.test(str);

}

​