Visual website monitoring

When you think about website monitoring usually you recall uptime monitoring (if the website is up and running) or infrastructure servers monitoring (to see how busy servers are).

But there are some other things you would love to monitor when you have website. For example it would be great to actually check if pages are working and there are no errors on them. Or you would like to keep checking and be notified immediately if your website was hacked.

This is where automated visual monitoring could play a good role.


Hacked or defaced website

One of most popular actions that hackers do when they deface the website is either change its content or add a javascript that will silently redirect users to some other site. In this case it is pretty hard to monitor that something changed as web server still responds with 200 response (everything is OK, server is working). With visual testing tool that creates screenshots we could catch these changes immediately. Under the hood we start the browser so it will be able to follow the javascript redirect and in this way screenshot of hacked web page will be very different and notification to site owner will be sent.


Problems with redirects

If you are working on the website and moving content around (changing its URLs) you would love to be sure that whatever happens content is accessible using old URLs. This is another use case where usual monitoring tools like checking response status won't work that well. In case of visual testing we can ensure that visually page stays the same after all the redirects. In our practice we even had situations with inifinite redirects that are very nasty problems. These types of problems are very easy to track if you set all your website monitored regularly with automated visual testing.


Problems with server, error messages on code level

Another big part of potential problems is of course if server starts to fail and produces 5xx or 4xx errors instead of serving pages. Or even worse after update of your server software (version of php, php libraries, mysql etc.) you start getting errors displayed on web pages. In this case automated visual testing also would be able to give you report where changes happened and let your development team react fast to fix bugs.

Please share your thoughts in comments what kind of other monitoring you use on your projects? Maybe you use visual monitoring to catch some other cases?