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Sergey Chernyshev edited this page Jan 27, 2019 · 11 revisions

Show Slow was an open source tool that helped monitor various website performance metrics over time.

!!! This project is obsolete and is no longer maintained !!!

For tracking of synthetic metrics we suggest checking out which is actively developed and maintained.

However if your goal is to track metrics, we suggest using Real User Measurement (RUM) tools instead, check out library which power most if not all commercial tools like that.

ShowSlow captures the results of YSlow rankings and similar performance metrics from other tools like WebPageTest and graphs them, to help you understand how various changes to your site affect its performance.


>>> Demo site is discontinued as of June 1, 2017 - please install your own instance <<<

Open Source project

This project is managed here on GitHub

ShowSlow Installation and configuration

Upgrading existing instance

Automated testing

To have your ShowSlow instance collect data automatically for URLs entered by users, you need to configure your tools and use automation scripts to run them on periodically (using cron, for example).

To get a list of URLs in the instance call page and to get a list of URLs that do not have any data collected yet (for more frequent monitoring), call

Configuring Tools


You can ask questions and open a tickets in our issue tracker


You can contribute by:

  • installing Show Slow and submitting issues
  • adding features or fixing bugs and Submitting code
  • by writing a good article in your blog about your experience using Show Slow or some particular problem it helped you solve
  • designers can contribute good design
  • business people can contribute by asking their tech teams to use Show Slow

Editing these pages

If you see some error or typo on this site, just click edit at the top and fix it - it's a wiki

Same goes for documentation omissions or any other useful information about the project.