How to make a redirect in PHP?

1. Basic answer

You can use the header() function to send a new HTTP header, but this must be sent to the browser before any HTML or text (so before the  declaration, for example).

header('Location: '.$newURL);

2. Important details

die() or exit()

header("Location: http://example.com/myOtherPage.php");
die();

Why you should use die() or exit(): 

Absolute URL

The URL must be an absolute. See RFC 2616. But in most cases a relative URL will be accepted too.

Status Codes

PHP's "Location"-header still uses the HTTP 302-redirect code, but this is not the one you should use. You should consider either 301 (permanent redirect) or 303 (other).

Note: W3C mentions that the 303-header is incompatible with "many pre-HTTP/1.1 user agents. Currently used browsers are all HTTP/1.1 user agents. This is not true for many other user agents like spiders and robots.

3. Documentation

HTTP Headers and the header() function in PHP

• What the PHP manual says
• What Wikipedia says
• What the W3C says

4. Alternatives

You may use the alternative method of http_redirect($url); which needs the PECL package pecl to be installed.

5. Helper Functions

This function doesn't incorporate the 303 status code:

function Redirect($url, $permanent = false)
{
    header('Location: ' . $url, true, $permanent ? 301 : 302);

    exit();
}

Redirect('http://example.com/', false);

This is more flexible:

function redirect($url, $statusCode = 303)
{
   header('Location: ' . $url, true, $statusCode);
   die();
}

6. Workaround

As mentioned header() redirects only work before anything is written out. They usually fail if invoked inmidst HTML output. Then you might use a HTML header workaround (not very professional!) like:

  http-equiv="Location" content="http://example.com/">

Or a Javascript redirect even.

window.location.replace("http://example.com/");