Installing and Managing PHP Extensions in DirectAdmin: A Detailed Guide

PHP extensions add abilities to PHP itself: image resizing with gd or imagick, international text with intl and mbstring, database drivers such as pdo_mysql. On Domain India's DirectAdmin shared hosting the extensions are installed at server level, so you can check what is available and ask for what is missing, but you cannot install one yourself. This guide shows what our DirectAdmin PHP builds include, how to check your own site, and what to do on a server you control.

1. Why you can't install extensions on shared hosting

An extension is compiled into, or loaded by, the server's PHP build. Every account on the server shares those builds, so adding one needs root access and a rebuild. That is why:

• there is no "install extension" button in your DirectAdmin panel;
• dl(), which would load an extension at runtime, is disabled on our servers;
• a php.ini or .user.ini line such as extension=redis.so does nothing on shared hosting.

What you can do is choose the PHP version per domain, and each version has its own set of extensions. See Changing PHP version in DirectAdmin.

2. What our DirectAdmin PHP builds include

Measured on our DirectAdmin server on 23 September 2026, using each version's command-line PHP. Your website normally loads the same set; if a check on your site disagrees, trust the site check.

Not present on any version when we measured: redis, memcached, apcu, mongodb, pgsql and pdo_pgsql, gmp, ldap and bz2. If your application needs one of these, ask support before you build around it.

PHP 8.3 is the version to choose for new sites. If you rely on imagick or OPcache, note the 8.3 column; for OPcache see the PHP OPcache guide.

3. Check which extensions your site has

Create a file with a hard-to-guess name, such as ext-7f3a9.php, in the domain's public_html folder:

<?php
foreach (['gd', 'imagick', 'intl', 'mbstring', 'pdo_mysql', 'zip', 'redis'] as $ext) {
    echo $ext, ': ', extension_loaded($ext) ? 'loaded' : 'missing', "\n";
}
echo 'PHP ', PHP_VERSION;

Open it in your browser, read the result, then delete the file. Change the list to the extensions your application asks for. To see every loaded extension, replace the loop with print_r(get_loaded_extensions());.

In WordPress, Tools › Site Health › Info › Server also lists key extensions, and Site Health warns when a recommended one is missing.

4. How to ask for an extension

Some extensions are not offered on shared hosting because they need a background service (Redis, Memcached, MongoDB) or are unsafe for a shared server.

5. PHP libraries are not extensions

Composer packages such as monolog/monolog or guzzlehttp/guzzle are plain PHP code in your project's vendor folder. You don't need the server's help for them. Composer isn't pre-installed, but with jailed SSH (on request) you can download composer.phar and run php composer.phar install; if it stops with a proc_open message, run it again with --no-scripts. Or:

1. run composer install --no-dev --optimize-autoloader on your own computer or in CI, with the same PHP version as the site;
2. upload the project, including vendor, with FTP or the DirectAdmin File Manager.

Check composer.json for lines such as "ext-intl": "*": those are extensions the server must have, so compare them with section 2. For the list of disabled functions, see PHP disabled functions on shared hosting.

6. On your own VPS with DirectAdmin

A Domain India VPS is self-managed and comes without a control panel. If you install DirectAdmin on it with your own licence, you have root access and manage PHP with CustomBuild:

cd /usr/local/directadmin/custombuild
./build update
./build set_php imap yes     # mark the extension for the build
./build php_imap             # compile and enable it

Replace imap with the extension you need, if CustomBuild supports it. Check the result with php -m for each PHP version, and restart PHP-FPM if the site does not see it yet. For extensions CustomBuild doesn't offer, follow DirectAdmin's own documentation rather than appending lines to php.ini by hand: a wrong extension= line can stop PHP from starting.

Good habits on your own server: enable only the extensions you use, rebuild after PHP updates, and test on a copy of the site before changing production.

7. Where Domain India hosting fits

Our DirectAdmin plans give you seven PHP versions per domain with the common extensions already built in, plus Softaculous, free Let's Encrypt SSL and weekly JetBackup backups. The price on the card is live and excludes 18% GST.

If your application needs Redis, MongoDB or an extension shared hosting doesn't offer, a VPS gives you full root access, and the App Platform runs apps in containers you define with a Dockerfile.

Ready to check your site? Upload the test file from section 3, then open a ticket with anything that is missing, or compare DirectAdmin hosting plans.