Summary: I am sorry. I mean the tideway module for PHP, which is free. The ui indeed is not free. It has pre-compiled binaries for various platform ... I have no experience in managing a server for a lot of people, and don't know if that is safe enough. If tideways is not good, I was thinking about XHProf on PHP 5.6. So that I can profile on PHP5.6, and then switch to PHP 7.1 for production. The result may not be accurate, but that might still give some ideas. It is a pity that Facebook stopped developing XHProf when they switch from Apache to developing HHVM for running PHP a while ago. Wikipedia also runs on HHVM now ... Mediawiki's help for profiling says the extension is free but the ui is not. (mediawiki.org) "Starting with MediaWiki 1.29, you can also use tideways, which additionally supports PHP 7. Tideways also advertises a seemingly proprietary UI to visualize results, but if you follow the instructions for without the UI, it should be fine. Installing the php-tideways Debian/Ubuntu package also just includes the PHP extension." The tideway ui currently still costs money but the php extension is free (tideways.io) UI is not free: "Try Tideways Profiler UI for free ... start free 30 days trial." Don't need account to install extension: "You can install Tideways PHP Extension in various ways, it is not necessary to have an account for the Tideways product." The github repository is definitely free: "We recommend to use our pre-compiled packages ...If you want to compile ... head over to github" Precompiled binaries (https://tideways.io/profiler/downloads) The tideways module for php can be installed for free at least a year ago (stackoverflow)"echo 'deb http://s3-eu-west-1.amazonaws.com/qafoo-profiler/packages debian main' > /etc/apt/sources.list.d/tideways.listwget -qO - https://s3-eu-west-1.amazonaws.com/qafoo-profiler/packages/EEB5E8F4.gpg | sudo apt-key add - sudo apt-get update sudo apt-get install tideways-php tideways-daemon" Those installation commands seems up to date (tideway installation manual) echo 'deb http://s3-eu-west-1.amazonaws.com/qafoo-profiler/packages debian main' > /etc/apt/sources.list.d/tideways.listwget -qO - https://s3-eu-west-1.amazonaws.com/qafoo-profiler/packages/EEB5E8F4.gpg | sudo apt-key add -sudo apt-get updatesudo apt-get install tideways-php tideways-daemon Mediawiki has a script that display profiling information, and it can use tideway without the ui (mediawiki.org)"... provides an Xhprof-backed profiler that captures profiling data for all functions as well as sub-functional units ... Even if you are using Tideways, still specify the ProfilerXhprof class."