Sometimes, there are non human (bots) that visit your website. These bots can have many purposes (such as security scanning, performance scanning, monitoring, search engine bot, spam bot, etc.). Often, you do not want these bots to be tracked in Piwik, because you may want to focus on how humans use the website, and not bots. In this case, you can tell Piwik to exclude traffic where the User-Agent of these requests match a given string.
To exclude traffic for a particular User agent (or several user agents), go to “Administration”, click on “Websites”. Below the list of websites, you will find the option to specify “Global list of user agents to exclude”. You can enter there a list of user agents to exclude from being tracked by Piwik. If the visitor’s user agent string contains any of the strings you specify, the visitor will be excluded from Piwik. You may also toggle the checkbox “Enable website specific user agent exclusion.” to enable this feature as a new column for each website in the Websites listing.
Note: when you exclude some traffic, it will only exclude it going forward and is not applied retroactively.