.PB File Extension

Program file containing source code created with PureBasic; based on the BASIC programming languauge; may include variables, functions, and references to other source files.

A PB file is a settings file used by Chromium-based web browsers, such as Google Chrome and Microsoft Edge. It is always named preloaded_data.pb, and it contains a list of websites for which a browser is allowed to autoplay video and audio. Google sets the default list of websites that preloaded_data.pb contains.

In version 62 of Chrome, Google introduced a feature known as the Media Engagement Index (MEI). This feature logs when and how many times you play video and audio on websites. After you choose to play video or audio on a website a certain number of times, Chrome automatically allows that website to autoplay video and audio.

When introducing MEI, Google created a default list of websites that could always autoplay videos and audio. This list is saved in the file preloaded_data.pb. After your browser determines a site should be allowed to autoplay video and audio, the browser adds that site to preloaded_data.pb. However, preloaded_data.pb is a binary file, so users cannot simply open the file to view or edit the website list it contains.

NOTE: In Windows, a browser's PB file is stored in its MEIPreload directory.

You can use the Python script unpack_dafsa.py to convert a preloaded_data.pb file's contents to plain text. This will allow you to view the list of websites your preloaded_data.pb file contains.