The issue of website monitoring testing frequency is a difficult one. Some website owners settle for a check every four hours, while others set the test frequency at 15 seconds. Most testing services increase their price with the requested frequency. So, rapidly repeated tests can end up costing a lot of money. Each test also puts a little load on the host of the website, so a high frequency of tests can impair the performance of the site. As a compromise, aim for a frequency of 5 to 15 minutes. However, if you have a high value site, increase that to a test every minute.