Requirements

Kestello runs on ordinary web hosting: shared hosting, a virtual server (VPS) or Docker. It needs PHP, a database and a web server, and nothing else. There is no Node.js, Composer or other tool to install on the server.

Use this page to check a hosting plan before you buy it, or to check the server you already have. The installer checks the same things again on its first screen, so you will not get halfway through an installation and find out something is missing.

In short

	Minimum	Recommended
PHP	8.4	8.5
Database	MySQL 8, MariaDB 10.6, PostgreSQL 13 or SQLite 3.35	MySQL 9.7 or PostgreSQL 18
PHP memory limit	128 MB	256 MB
Disk space	200 MB plus your uploads and backups	1 GB free at all times
Web server	Apache with .htaccess support, or nginx	Either, with HTTPS

Most hosting plans sold in the last few years meet this. If your host offers a choice of PHP versions in its control panel, pick the newest it offers, and at least 8.4.

PHP

Kestello needs PHP 8.4 or newer. PHP 8.4 receives security fixes until the end of 2028, and PHP 8.5 until the end of 2029. On an older PHP, every page shows a short message saying which version is needed. Site Health (under System → Site Health) warns you when the PHP version your site runs on stops getting security fixes.

Extensions

PHP comes in pieces called extensions. Hosts turn most of them on by default; some control panels have a page where you can switch them on yourself.

Required. Kestello will not install without these:

Extension	Used for
pdo and one of pdo_mysql, pdo_pgsql or pdo_sqlite	Talking to the database. You only need the one for the database you use.
mbstring	Handling text in every language correctly
sodium	Encryption and checking the signatures of plugins and updates
json	The admin and the API
zlib	Backups, packages and compressing pages
ctype	Checking form input

Recommended. Kestello works without these, with the limits described:

Extension	Without it
gd or imagick	Images are stored as uploaded. No resized versions, no WebP or AVIF. With imagick, AVIF support depends on how the host built it.
intl	Dates, numbers and plural forms are not localised for your visitors' language.
fileinfo	Kestello cannot double-check the real type of uploaded files as reliably.
curl	Connections to other services (mail providers, search engines, update checks) are slower and less reliable.
opcache	Every page takes noticeably longer to build.

After installing, System → Site Health lists any recommended extension that is missing.

PHP settings

Setting	What to use	Why
memory_limit	128M or more	Resizing large photos needs memory.
upload_max_filesize	The largest file you will upload, for example 64M	Larger uploads are refused by PHP before Kestello sees them.
post_max_size	Equal to or larger than upload_max_filesize	If it is smaller, large uploads fail without a clear error.
max_execution_time	60 or more	Backups and updates of large sites take a while. Kestello asks for more time when it can, but some hosts do not allow that.

Database

Kestello works with any of these, and you can move a site from one to another later with a backup:

• MySQL 8.0 or newer, or MariaDB 10.6 or newer. Offered by nearly every host. The usual choice.
• PostgreSQL 13 or newer. Common on managed cloud platforms.
• SQLite 3.35 or newer. The database is a single file inside the site's storage folder, so there is nothing to set up. Good for small sites and trying Kestello out. Not a good fit for sites with many editors saving at the same time.

For MySQL, MariaDB and PostgreSQL you need a database and a user that can create tables in it. Most control panels have a "MySQL databases" page that creates both and shows you the details. Write down the database name, the user name, the password and the host (often localhost). The installer asks for them.

Web server

Kestello's front door is the file public/index.php. The web server has to send every request it cannot answer with a real file to that file.

• Apache (most shared hosting): Kestello ships .htaccess files that do this. Your host must allow .htaccess files and have mod_rewrite on. Almost all do.
• nginx: needs a short configuration block, shown in Installing Kestello.
• Others (Caddy, LiteSpeed, IIS): any server that can point the site at public/ and route unknown paths to public/index.php works.

Ideally the site's document root (the folder the web server shows to visitors) is the public folder. If your host does not let you choose it, Kestello's top-level .htaccess file sends visitors to public for you and keeps the other folders out of reach.

Folders PHP must be able to write to

Kestello writes to a few folders: the installer saves its settings, uploads are stored, backups and caches are written. The PHP process needs write access to:

Folder	Why
config/	The installer writes the database details and site settings here.
storage/	Caches, logs, sessions, backups, and the SQLite database if you use one.
content/	Uploads, and plugins or themes you install from the admin.
core/	Only if you want to update Kestello itself from the admin.

On shared hosting this is usually already the case. On a VPS, the folders must belong to the user the web server runs PHP as (often www-data).

Background tasks

Some work happens in the background: sending email, making image sizes, nightly backups, publishing scheduled content. Kestello can do this in two ways:

• With a cron job (recommended). Most control panels have a "Cron jobs" page. Add one that runs every minute. The exact line is shown in Installing Kestello.
• Without one. If your host has no cron, Kestello runs due tasks at the end of ordinary page visits. This works, but tasks run late on a quiet site.

HTTPS

Use HTTPS for any site that is on the internet. Without it, passwords travel unencrypted. Most hosts provide free certificates (often labelled "Let's Encrypt" or "SSL"). Site Health warns you when a live site runs without HTTPS.

Next

Install Kestello.