If you want to make your URL valid according to the W3C standards, examine the following items one by one and check: 1.      In order for your URL to be secure, it must begin with HTTP or HTTPS. 2.      Your website should have www at the start of your website (which means world web consortium anyway) 3.      Make sure that the last part of your URL is a top-level domain. For example, some of these can be listed as com, org, net.