PHP Compatibility Index

Is Custom CSS and JavaScript compatible with PHP 8?

Version 2.0.16 · 10,000+ active installs

No PHP 8.0–8.5 problems found

No removed or deprecated PHP features found in Custom CSS and JavaScript 2.0.16 for PHP 8.0 to 8.5.

PHP 8.0
✓
PHP 8.1
✓
PHP 8.2
✓
PHP 8.3
✓
PHP 8.4
✓
PHP 8.5
✓

✓ no problems · ⚠ deprecation notices only (still works) · ✗ uses something removed in that PHP version

Not updated for 2.2 years. Nobody seems to maintain this plugin, so problems found here are unlikely to be fixed. If your site uses it, look for a maintained alternative before upgrading PHP.
Check your whole site, not just one plugin. The free PHP Upgrade Check plugin scans every plugin and theme you have installed (including premium and custom ones) and explains each problem. It runs on any host.

Removed long ago or protected by a check (code that most likely never runs on PHP 8)

File:lineWhat
custom-css-and-javascript.php:97Function get_magic_quotes_gpc() is deprecated since PHP 7.4 and removed since PHP 8.0

Plugin page on WordPress.org: custom-css-and-javascript