How to install PHP 8 on Mac OS

First install Homebrew

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install stable version of php using Homebrew

brew install php

This will start updating Homebrew – Updating tap and Formulae.
The following dependencies will normally be installed through the command above. If your differs, the dependencies will install when it is necessary.

apr, apr-util, argon2, aspell, m4, autoconf, brotli, gettext, libunistring, libidn2, libmetalink, libssh2, c-ares, jemalloc, libev, nghttp2, openldap, rtmpdump, zstd, curl, libtool, unixodbc, freetds, libpng, freetype, fontconfig, jpeg, libtiff, webp, gd, libffi, glib, gmp, icu4c, krb5, libpq, libsodium, libzip, oniguruma, pcre2 and tidy-html5

After all dependencies installation

To enable PHP in Apache add the following to httpd.conf and restart Apache:

LoadModule php_module /usr/local/opt/php/lib/httpd/modules/libphp.so

<FilesMatch \.php$>
   SetHandler application/x-httpd-php
</FilesMatch>

Finally, check DirectoryIndex includes index.php

    DirectoryIndex index.php index.html

The php.ini and php-fpm.ini file can be found in:

    /usr/local/etc/php/8.0/

To have launchd start php now and restart at login:

  brew services start php

Or, if you don’t want/need a background service you can just run:

  php-fpm