Total Playtime WebExtension does not collect any personal information. Unlike the original Total Playtime website, this extension does not communicate with a central server under my control. However, it does interact with the Steam API, which is governed by Steam's Privacy Policy. This extension will not make any network requests of any kind until you press the "Total Playtime" button on a Steam profile page. If you press that button, the Steam ID64 of the profile that you are viewing will be sent to Steam servers directly to retrieve playtime information about that profile. Nothing more.

This extension is not affiliated with or made by Steam or Valve Corporation. In case you didn't know that already.