How to Enable or Disable PHP Extensions in cPanel

Some applications won’t run until a particular PHP extension is switched on – you might see a message like “the mbstring extension is required” or “intl not found”. Extensions are optional add-ons that give PHP extra abilities, such as working with images, connecting to databases, or handling special characters. On every JetHost web hosting plan you can turn them on or off yourself in cPanel. This guide explains what they are and how to manage them.

What PHP extensions are

PHP on its own handles the basics. Extensions bolt on extra functionality so PHP can do specialised jobs – resize an image, talk to a MySQL database, encrypt data, or parse XML. Instead of building every feature into PHP and making it heavier for everyone, these capabilities are kept as separate modules you enable only when you need them. Most common extensions are already active on JetHost, but applications sometimes ask for a less common one, and that’s when you need to switch it on.

Enable or disable an extension

1. Log in to cPanel and open Select PHP Version in the Software section.
2. Click the Extensions tab. You’ll see a long list of modules, each with a checkbox.
3. Tick a box to enable an extension, or untick it to disable one.
4. Changes save automatically – there’s no separate apply button.
5. Reload your site to confirm the error is gone.

Extensions are tied to a specific PHP version. If you later switch to another PHP version, check that the same extensions are enabled there too, since each version keeps its own list.

Commonly needed extensions

• mbstring – handles multi-byte text (accents, non-Latin alphabets, emoji). Many modern apps require it.
• intl – internationalisation: locale-aware formatting of dates, numbers, and currencies.
• gd or imagick – image processing, used for thumbnails and resizing.
• curl – lets scripts make outgoing requests to other servers and APIs.
• zip – create and extract ZIP archives, often needed by plugin and theme installers.

Only enable what you need

It’s tempting to switch everything on, but each active extension uses a little memory and adds to what has to load on every request. Enabling only the extensions your applications actually use keeps PHP lean and your site responsive. If you’re unsure whether something is still needed, it’s safe to disable it and test – you can always switch it back on if a page breaks.

Need more help?

An application needs an extension you can’t find in the list? Open a ticket through Client Area → Support Tickets and our team will check whether it can be enabled for you.