There are two main ways to run a PHP session without cookies by manually passing the session ID. First, enable URL session ID propagation, and enable PHP to automatically attach the session ID to the link by setting session.use_cookies=0, session.use_only_cookies=0 and session.use_trans_sid=1 in php.ini; second, manually process the session ID, obtain it through session_id() and explicitly pass it in the link or form, and read the ID to restore the session on the subsequent page. Pay attention to security risks such as session fixation, historical leakage and caching issues. Session_regenerate_id() should be used, avoid publicly exposing IDs, and give priority to using cookies with the HttpOnly/Secure flag.

You can use PHP sessions without cookies by passing the session ID manually through URLs or other methods. The default behavior for PHP sessions is to store a session ID in a cookie, but if you need to support environments where cookies are disabled or blocked, there are alternative approaches.

Here's how you can make it work effectively.

How PHP Sessions Normally Work

By default, when you start a session using session_start() , PHP creates a unique session ID and stores it in a cookie on the user's browser. That session ID is then sent back to the server with each request so PHP can retrieve the correct session data.

But what happens if cookies aren't available? PHP still generates a session ID, but it won't be automatically passed between requests. So you have to pass it yourself — typically via the URL or hidden form fields.

Enabling Session IDs in URLs

PHP has built-in support for appending the session ID to URLs. This feature is controlled by two settings in your php.ini file:

• session.use_cookies – controls whether PHP sends the session ID using cookies.
• session.use_only_cookies – tells PHP to only use cookies for session IDs (disable this).
• session.use_trans_sid – enables transparent session ID propagation via URLs.

To enable session IDs in URLs, set these values ??like this:

 session.use_cookies = 0
session.use_only_cookies = 0
session.use_trans_sid = 1

Once configured, PHP will automatically append the session ID to any internal links that are properly formatted. For example:

 <?php session_start(); ?>
<a href="page.php">Go to page</a>

The generated link might look like this:

 page.php?PHPSESSID=abc123xyz

?? Important: Only use this method if absolutely necessary. Passing session IDs in URLs can expose them in referrer headers and browser history, which poses security risks.

Manually Handling Session IDs

If you want more control over how the session ID is passed, you can handle it manually. Here's how:

1. Start the session as usual:

    session_start();

2. Get the session ID:

    $sid = session_id();

3. Append it to links or forms:

    echo &#39;<a href="next_page.php?sid=&#39; . $sid . &#39;">Continue</a>&#39;;

4. On the next page, read the session ID from the URL and resume the session:

    if (isset($_GET['sid'])) {
       session_id($_GET['sid']);
   }
   session_start();

   This approach gives you full control and avoids relying on PHP's automatic behavior. You can also pass the session ID via POST requests or JavaScript variables if needed.

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   Security Considerations

   Passing session IDs via URLs introduces some security concerns:

   • Session fixation : If someone guesses or captures a session ID, they can impersonate the user.
   • History leak : Browsers store URLs with session IDs in history, logs, and referrer headers.
   • Caching issues : URLs with session IDs may get cached by proxies or browsers.

   To mitigate these risks:

   • Always regenerate the session ID after login using session_regenerate_id() .
   • Avoid exposing session IDs publicly.
   • Prefer cookies when possible, since they offer better security options (like HttpOnly and Secure flags).

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   Summary

   Using PHP sessions without cookies is doable but requires careful handling. You can either rely on PHP's built-in transparent SID support or manage the session ID manually via URLs or form fields. Just remember that while this method works in restricted environments, it comes with trade-offs in terms of security and usability.

   Basically that's it.

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