PART files are created by the Mozilla Web Browser and some download manager programs such as JDownloader, Go!Zilla, FlashGet, eMule, eDonkey and Free Download Manager.

The purpose of PART files is to store the information of partially downloaded files so that the download process can be resumed at a later time.

Some download managers may break down larger files into several smaller ones giving each of them the .part extension. When the download process is completed all these files are merged into a larger one that is also renamed to its initial extension. Single files are also given the .part extension and renamed after the download is complete.

How to open PART Files

PART files can be found in the "Unfinished Downloads" folder of the download manager or of Mozilla Firefox. Since the files are incomplete, opening and using them is impossible most of the time. The best thing to do is to try and resume the download using one of the download managers or one of the special Firefox plug-ins such as DownThemAll.

If the download stopped because of a power outage or crash and resuming it is impossible, renaming the file to its initial extension may sometimes make it usable. This applies mostly to audio and video files.