How to add http:// if it doesn't exist in the URL

Question

How can I add http:// to a URL if it doesn't already include a protocol (e.g. http://, https:// or ftp://)?

Example:

addhttp("google.com"); // http://google.com
addhttp("www.google.com"); // http://www.google.com
addhttp("google.com"); // http://google.com
addhttp("ftp://google.com"); // ftp://google.com
addhttp("https://google.com"); // https://google.com
addhttp("http://google.com"); // http://google.com
addhttp("rubbish"); // http://rubbish

If you had, mozilla.org alone, how would you know if it should be, http, https or ftp? — Anthony Forloney
– Anthony Forloney, Commented May 4, 2010 at 0:25
@Anthony: he says he wants to add "http://" if there's no other protocol. — nickf
– nickf, Commented May 4, 2010 at 0:27
@Anthony But when the user types the url without http:// or anything, do you expect it to be ftp:// or something? — CodeOverload
– CodeOverload, Commented May 4, 2010 at 0:28

Alix Axel · Accepted Answer · 2010-05-04 00:30:32Z

273

A modified version of @nickf code:

function addhttp($url) {
    if (!preg_match("~^(?:f|ht)tps?://~i", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

Recognizes ftp://, ftps://, http:// and https:// in a case insensitive way.

answered May 4, 2010 at 0:30

Alix Axel

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2 Comments

Luis Lobo Borobia Over a year ago

Having compared addhttp and addscheme below, I've come to the conclusion that addscheme is better in terms of performance:

$url = "www.google.com"; $init = microtime(true); for( $i = 1; $i < 100000; $i++ ) { 	addScheme( $url ); }  echo  microtime(true) - $init; echo "<BR>";  $init = microtime(true); for( $i = 1; $i < 100000; $i++ ) { 	addhttp( $url ); } echo  microtime(true) - $init;

holden321 Over a year ago

What if url begins with '//'?

Dave Jarvis · Accepted Answer · 2014-01-08 22:12:35Z

151

At the time of writing, none of the answers used a built-in function for this:

function addScheme($url, $scheme = 'http://')
{
  return parse_url($url, PHP_URL_SCHEME) === null ?
    $scheme . $url : $url;
}

echo addScheme('google.com'); // "http://google.com"
echo addScheme('https://google.com'); // "https://google.com"

4 Comments

Tom Auger Over a year ago

This should be the selected answer - why roll your own when the language has native support? Nice work.

Randy Johnson Over a year ago

One improvement that could be made with this function is checking to see if the field has a value so it is not adding an http to an empty field.

Taylan Over a year ago

This doesn't work with relative protocols. e.g. echo addScheme('//google.com');

Ja͢ck Over a year ago

@Taylan Yeah, you would have to ltrim($url, '/')

Peter Mortensen · Accepted Answer · 2020-11-06 16:28:43Z

52

Simply check if there is a protocol (delineated by "://") and add "http://" if there isn't.

if (false === strpos($url, '://')) {
    $url = 'http://' . $url;
}

Note: This may be a simple and straightforward solution, but Jack's answer using parse_url is almost as simple and much more robust. You should probably use that one.

edited Nov 6, 2020 at 16:28

Peter Mortensen

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answered May 4, 2010 at 0:44

Brenton Alker

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Comments

ThisDude · Accepted Answer · 2024-09-19 14:07:08Z

5

The best answer for this would be something like this:

function addScheme($url, $scheme="http://" )
{
  return empty(parse_url($url)['scheme']) ? $scheme . ltrim($url, '/') : $url;
}
// Test below
$url = 'google.com';
echo addScheme($url,"ftp://"); // "https://google.com"
echo addScheme('google.com'); // "http://google.com"
echo addScheme('https://google.com'); // "https://google.com"

The protocol flexible, so the same function can be used with ftp, https, etc.

edited Sep 19, 2024 at 14:07

answered Jul 29, 2017 at 2:33

ThisDude

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Comments

Peter Mortensen · Accepted Answer · 2020-11-06 16:20:36Z

2

Scan the string for ://. If it does not have it, prepend http:// to the string... Everything else just use the string as is.

This will work unless you have a rubbish input string.

edited Nov 6, 2020 at 16:20

Peter Mortensen

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answered May 4, 2010 at 0:32

Rosdi Kasim

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2 Comments

CodeOverload Over a year ago

i'de prefer a regex version :)

Rosdi Kasim Over a year ago

Don't be too quick on regex. Regex tends to be hard to read and it could introduce another problem/bug once the problem grows.

Peter Mortensen · Accepted Answer · 2020-11-06 16:18:12Z

0

Try this. It is not watertight¹, but it might be good enough:

function addhttp($url) {
    if (!preg_match("@^[hf]tt?ps?://@", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

_{1. That is, prefixes like "fttps://" are treated as valid.}

edited Nov 6, 2020 at 16:18

Peter Mortensen

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answered May 4, 2010 at 0:25

nickf

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1 Comment

kamasheto Over a year ago

This would match (ergo return true and if would evaluate to false) weird combinations.. like htps, fttps, fttp, htp, I guess.

Peter Mortensen · Accepted Answer · 2020-11-06 16:19:50Z

0

nickf's solution modified:

function addhttp($url) {
    if (!preg_match("@^https?://@i", $url) && !preg_match("@^ftps?://@i", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

edited Nov 6, 2020 at 16:19

Peter Mortensen

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answered May 4, 2010 at 0:30

kamasheto

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1 Comment

Alix Axel Over a year ago

I believe ftps:// is also valid.

ncica · Accepted Answer · 2023-10-09 15:37:42Z

-1

<?php
    if (!preg_match("/^(http|ftp):/", $_POST['url'])) {
        $_POST['url'] = 'http://'.$_POST['url'];
    }
    $url = $_POST['url'];
?>

This code will add http:// to the URL if it’s not there.

edited Oct 9, 2023 at 15:37

ncica

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answered Jan 17, 2013 at 4:08

ayan

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