PHP Code Showing as Plain Text Instead of Running

When you open a page and see <?php echo "Hello"; ?> in the browser instead of Hello, or the page is blank where output should be, PHP never ran. The web server handed the file straight to the browser. That happens for five reasons, and the first two account for almost every beginner case: the file was opened directly from the disk rather than through a server, or it has the wrong extension.

Cause 1: you opened the file, not a URL#

Look at the address bar. If it starts with file:// or shows a path like C:/xampp/htdocs/test.php, the browser read the file from disk. No server was involved, so no PHP ran. The browser shows PHP source because it does not know what else to do with it.

PHP runs on a server, and the browser must ask the server for the page:

http://localhost/test.php          # XAMPP, WAMP: file in htdocs or www
http://localhost:8888/test.php     # MAMP default port
http://localhost:8000/test.php     # PHP's built-in server, below

The quickest server of all is built into PHP itself. From the folder containing your file:

php -S localhost:8000

Then open http://localhost:8000/test.php. If that works and XAMPP does not, the problem is XAMPP configuration, not your code.

Cause 2: the file is not .php#

A file named index.html is served as HTML no matter what is inside it. PHP inside it is shown as text, or, since browsers treat <?php as an unknown tag, silently hidden. Rename the file to .php. Editors that “helpfully” append .txt or keep .html are a common cause; check the real extension in the file manager with extensions shown.

Cause 3: the file is in the wrong folder#

Each local server stack serves one specific folder:

A file on the Desktop cannot be reached through localhost. Move it into the served folder, or point the built-in server at wherever it is.

Cause 4: the server is not running#

In the XAMPP or MAMP control panel, Apache must show as running, in green. If the browser says “This site can’t be reached” or “connection refused”, it is not. Start it. If it refuses to start, something else is using port 80 — on Windows, commonly Skype, IIS or the World Wide Web Publishing service. The control panel’s log names the port conflict.

Cause 5: short tags#

Code written as <? echo "hi"; ?> without the php uses short open tags, which are disabled on most installations. PHP treats the block as literal text and the browser hides it as an unknown tag, so the output simply disappears. Always write the full tag:

<?php echo "hi"; ?>
<?= $name ?>          <!-- this short echo form is always enabled -->

Apache is running but PHP is not attached#

If the URL is right, the file is .php, and the browser still downloads the file or shows the source, Apache is serving it without a PHP handler. This is common after a system upgrade on Linux, and occasionally on a fresh manual Apache install. Test the PHP interpreter directly:

php -v                    # PHP itself works?
php test.php              # runs the file from the command line, ignoring the server

If both work, the fault is the Apache-to-PHP link. On Debian and Ubuntu that is the libapache2-mod-php package and a2enmod; on a manual install it is the LoadModule and AddType lines in httpd.conf. The XAMPP and MAMP bundles set this up for you, which is why they are the sensible starting point.

Blank page instead of source#

A completely blank page means PHP did run and then hit an error it is configured not to display. Add these two lines at the very top of the file, temporarily:

<?php
ini_set('display_errors', '1');
error_reporting(E_ALL);

Reload, and the error appears with its line number. Remove the lines before deploying; errors belong in the log on a live site.

Where to go next#

• PHP errors not showing — the blank-page case in depth.
• PHP not working with Apache on Ubuntu — when the handler is the problem.
• Introduction to PHP — how PHP and the server fit together.