The PEK file extension is associated with the Adobe Creative Suite, version 4 and later. Developed by Adobe Systems Inc., the suite is designed for video and audio editing, graphic design and web development. PEK files are created each time the user imports audio data into Adobe Soundbooth, Encore, After Effects or Premiere Pro.

For improved performance all the applications above use the Adobe Media Encoder, a standalone component of the Adobe Creative Suite, to create CFA files which are conformed to a proprietary format owned by Adobe. The new format is easier to access and to parse resulting in shorter processing times.

When creating and caching CFA files which contain audio data, the Adobe Media Encoder also creates PEK files. These contain the visual waveform data displayed on the audio track timeline. Both CFA and PEK files can be found and moved/deleted manually from the project directory but the Media Encoder will create them again if the data is needed. This can be avoided by disabling caching.