Enable error logging in PHP

Turn on error reporting to diagnose a blank page — to a log file, never to the browser on a live site.

Make PHP record errors so you can see what is failing. Applies to shared, reseller and Premium hosting.

A blank white page almost always means a fatal error with display disabled. Logging is how you see it.

Never enable display_errors on a live site. Error messages reveal file paths, database names and sometimes credentials, and attackers read them deliberately. Log to a file instead — the information is identical and only you can see it.

For one script

Add at the very top, before any other code:

<?php
ini_set('log_errors', 1);
ini_set('error_log', __DIR__ . '/error_log');
error_reporting(E_ALL);

Errors are written to error_log beside the script. Read it as described in Find your error log.

For the whole account

cPanel → Select PHP Version → Options:

Setting	Value
`log_errors`	`On`
`error_reporting`	`E_ALL`
`display_errors`	`Off` — leave it off

See Change your PHP version and settings.

WordPress

Edit wp-config.php, above /* That's all, stop editing! */:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );

Errors go to wp-content/debug.log.

WP_DEBUG_DISPLAY set to false is what keeps them off the page. Enabling WP_DEBUG alone shows errors to visitors — see Enable WP_DEBUG.

Debugging on a live site

If you must, restrict output to your own IP:

if ( $_SERVER['REMOTE_ADDR'] === '203.0.113.10' ) {
    ini_set( 'display_errors', 1 );
    error_reporting( E_ALL );
}

Remove it once finished.

Turn it off afterwards

Verbose logging writes on every request. Leaving E_ALL on a busy site produces a log file large enough to affect your disk quota, and the noise buries anything real.