PHP regex for url validation, filter_var is too permisive

Question

First lets define a \"URL\" according to my requirements.

The only protocols optionally allowed are http:// and https://

then a man

Answer 1

It may vary but in most of the cases you don't really need to check the validity of any URL.

If it's a vital information and you trust your user enough to let him give it through a URL, you can trust him enough to give a valid URL.

If it isn't a vital information, then you just have to check for XSS attempts and display the URL that the user wanted.

You can add manually a "http://" if you don't detect one to avoid navigation problems.

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I know, I don't give you an alternative as a solution, but maybe the best way to solve performance & validity problems is just to avoid unnecessary checks.