Common extensions, what they’re for
| Extension | Used by |
|---|---|
mysqli / pdo_mysql | Any MySQL connection from PHP. WordPress, Laravel, anything. |
gd | Image manipulation. WordPress media uploads, thumbnail generation. |
imagick | Higher-quality image manipulation than gd. Some plugins prefer it. |
intl | Internationalization functions. Composer packages frequently require it. |
mbstring | Multibyte string handling. Required by most modern PHP frameworks. |
xml, dom, simplexml | XML parsing. Often required by Composer itself, plus any RSS/SOAP code. |
curl | Outbound HTTP from PHP. Required by anything fetching APIs. |
zip | ZIP archive support. WordPress plugin/theme installs use it. |
bcmath / gmp | Arbitrary precision math. Crypto, finance, some Magento components. |
redis | Redis client. Object cache plugins, queue workers. |
opcache | PHP bytecode cache. Always on. Don’t turn it off. |
soap | SOAP/WSDL clients. A handful of payment gateways still need it. |
ldap | LDAP authentication. Rare on shared hosting. |
Apply changes
After ticking or unticking, click Save. The next PHP request loads the new extension list. There’s no service restart needed.How this differs from pecl install
The selector loads extensions that are pre-built for each PHP version. PECL lets you compile arbitrary extensions from source. The selector is faster, safer, and the right tool for 99% of cases. PECL only matters when:
- You need a specific patched build that the cPanel selector doesn’t expose.
- You’re testing a beta extension (e.g.,
apcubetas, custom builds ofimagick).
Common issues
A required extension isn't in the list
A required extension isn't in the list
Either it’s not packaged for our PHP build (rare for mainstream extensions; common for experimental ones), or it’s been deprecated. The most common surprise:
mcrypt was removed from PHP 7.2 onwards and is no longer in the list. Switch to openssl or sodium for modern crypto.I enabled an extension but PHP says it's missing
I enabled an extension but PHP says it's missing
Likely you ticked the box but didn’t click Save. The page accepts ticks without saving until you hit the button. Reload the page to confirm; ticked-and-saved extensions stay ticked across reloads.
Two extensions conflict (e.g., apc and apcu)
Two extensions conflict (e.g., apc and apcu)
Some extensions are mutually exclusive. The selector usually warns when you try to enable a conflicting pair. If your PHP suddenly errors on a function from one of them, untick the other.
Toggling an extension didn't take effect
Toggling an extension didn't take effect
Persistent processes like long-lived queue workers don’t pick up extension changes until they restart. The HTTP-handler PHP picks up changes on the next request; CLI cron jobs pick up changes on the next invocation. If you have a daemon, you need to restart it.