is URL valid or not

Question

Possible Duplicate:
what is the best way to check if a Url exists in PHP ?`

I'm looking for a function that returns TRUE or FALSE in php, either the URL is valid or not.

isValidURL($url); I think that simple... That would take into count all kind of URL possible.

By valid I want it to refer to an existing page of the web or other kind of files. It just should exist.

And valid means what? Syntactically valid? Or references an existing resource? — Gumbo, Jul 24 '11 at 13:05
hey guys thanks a lot for your help. By valid i want It to referes to an existing page of the web or other kind of files. It just should exist... — james, Jul 24 '11 at 13:17
possible duplicates of http://stackoverflow.com/search?q=check+if+url+exists+php — Gordon, Jul 24 '11 at 13:21
A valid url is defined by its RFC http://www.faqs.org/rfcs/rfc1738.html — fyr, Jul 24 '11 at 13:23
thanks everyone, sorry for the trouble. you still helped me a lot — james, Jul 24 '11 at 14:27
This many or may not be a duplicate, but it is not a duplicate of the question that it is linked to as a duplicate. This question is asking about "valid" URLs, that question is asking about "available" URLS. Entirely possible that a valid URL is not available. — ftrotter, Aug 02 '15 at 23:20

score 60 · Answer 1 · answered Jul 24 '11 at 13:19

60

<?php

$url = "http://stack*overflow.org";


if(filter_var($url, FILTER_VALIDATE_URL) === FALSE)
{
        echo "Not valid";
}else{
        echo "VALID";
}
?>

this does not check tlds though

answered Jul 24 '11 at 13:19

genesis

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this is good one, but your own example is validates to `true` ;) `http://stackoverflow.invalid`. So it's not reliable too ;-) – Nemoden Jul 24 '11 at 13:26
1

@Nemoden: I know it isn't. But I told that already in my post... – genesis Jul 24 '11 at 13:37
8

@Nemoden: What's wrong with the URL stackoverflow.invalid? You can setup your own local DNS to handle all sorts of TLD's. I have *.lan pointing to several local development sites behind a firewall. ;) – Dustin Graham May 20 '13 at 03:12
Note: this will also allow `http://stackoverflow` with no extension at all. – PaulSkinner Jun 19 '13 at 11:01
3

http://stackoverflow is also a valid url, extentions are not required for valid urls, localhost is a valid url too – Shahrokhian Aug 24 '13 at 09:21
I guess it's a good idea to use this first and than do more reliable but slower check using `get_headers()`. – Tomáš Zato Jan 19 '14 at 21:00
Note: neither `http://åäö.se` or even `http://example.com?s=åäö` is considered valid by this method. – Jonas Äppelgran May 20 '14 at 13:09
IPv6 addresses are also considered invalid by this method. – rink.attendant.6 May 20 '14 at 16:18
@JonasÄppelgran - Neither `http://åäö.se` nor `http://example.com?s=åäö` are valid URL, though browsers display those characters.Technically, the browser uses punycode to encode domain names and url-encodes parameters. So the correct URLs are `http://xn--4cab6c.se/` and `http://example.com/?s=%C3%A5%C3%A4%C3%B6` – Philipp May 04 '21 at 10:29

score 2 · Answer 2 · answered Jul 24 '11 at 13:06

2

You can check whether URL is valid or not using parse_url function which would return false if URL is not valid and an array otherwise.

function isValidURL($url) { return (bool)parse_url($url); }

pretty easy way, huh? :)

answered Jul 24 '11 at 13:06

Nemoden

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It isn't reliable:http://sandbox.phpcode.eu/g/a4192.php – genesis Jul 24 '11 at 13:15
2

Then `preg_match('|^http(s)?://[a-z0-9-]+(.[a-z0-9-]+)*(:[0-9]+)?(/.*)?$|i', $url);` isn't reliable too. But I have my own reason to don't care about domain zone: they will register more domain zones tommorow and I will have to add all of them in all my projects manually? To check if URL is REALLY exists I will use cURL or sockets. For quick check this functions is enough for me. I just propose it to the OP and I don't mind if he will not mark my answer as accepted. I just offer an approach which I use myself. And it's more clean rather than `regex` that's why I like it ;-) – Nemoden Jul 24 '11 at 13:24
not reliable? schema is good, you should check if it exists the name with gethostbyname: function isValidURL($url) { $parts = parse_url($url); if((bool)$parts) { return ($parts['host'] != gethostbyname($parts['host']);} else return false; } – Daniele Cruciani Sep 21 '12 at 06:16
2

The docs explicitly say "This function is not meant to validate the given URL"... – Kloar Nov 22 '12 at 10:19
@Kloar, "is not meant" does not mean "it can not". – Nemoden Nov 23 '12 at 01:11
yeah, +1 it doesn't really work... – Gabriel Queiroz Silva Apr 01 '16 at 19:36
@Nemoden it also can not though, there are absolutely tons of ways to get invalid urls through parse_url – Shardj Aug 07 '20 at 13:30

is URL valid or not

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