Check your plugins and themes before you switch to PHP 8.3 or 8.4.

Fizz Labs Upgrade Scanner for PHP reads the PHP code of every installed plugin and theme, finds functions, constants and syntax that were removed or deprecated in PHP 8.0 to 8.4, and shows you the file and line. It runs entirely on your server.

Know what to fix, file by file. Counts per plugin and theme, per PHP version, with the exact file:line and the php.net migration note behind every finding.
No data leaves your server. No external requests, no tracking, no account, no API key. The scan reads files locally and stores one report in your database.
Free and complete. Every feature is free: unlimited scans, CSV and JSON export, and a WP-CLI command (wp fizz-labs-upgrade-scanner-for-php scan) for agencies and CI.

Install the plugin, then go to Tools Fizz Labs Upgrade Scanner for PHP and click Scan plugins and themes.

What it checks

Removed in PHP 8.0: create_function(), each(), __autoload(), the (real) and (unset) casts, $php_errormsg, $str{0} offsets, money_format(), get_magic_quotes_gpc() and other removed functions.
Deprecated in PHP 8.1: strftime(), date_sunrise(), mhash(), FILTER_SANITIZE_STRING, Serializable without __serialize() and more.
Deprecated in PHP 8.2: utf8_encode(), utf8_decode() and “${var}” string interpolation.
Deprecated in PHP 8.3: get_class() without arguments, assert_options() and the ASSERT_* constants.
Deprecated in PHP 8.4: implicitly nullable parameter types, E_STRICT, trigger_error() with E_USER_ERROR, mysqli_ping(), lcg_value() and more. Functions of the IMAP, OCI8 and Pspell extensions, which moved from PHP core to PECL in 8.4.

Privacy

No data leaves your server. Fizz Labs Upgrade Scanner for PHP makes no external HTTP requests, sends no telemetry and sets no cookies. It reads plugin and theme files on your server and saves the latest report in your WordPress database (option phpups_last_report). Deleting the plugin removes that data.