What is .001 extension? Recently, my friend sent his wedding video with .001, .002 etc video format. With little research in Google I came to know that it is a split file. He has split 1GB file into five 200MB file. As there are five split files, the extension was changed to .001 to .005. For example: if the extension was wedding.avi then after conversion it changes to wedding.avi.001 to wedding.avi.005. It was easy for me to download it from Google drive as each file is only 200MB.
How to play the .001 video file? As I already told they are split files, you need to first join them. There are many freeware available to join these split files. I used HJSplit to join these split files. HJSplit is a cross-platform tool and is compatible with Windows, Linux and Mac OS.
You can download HJSplit from the official website. It will be downloaded as a zip file. You can see hjsplit.exe when you double click on the zip file. Double clicking on hjsplit.exe will launch the application. HJSplit doesn't need any installation, it will execute directly without installation.
Joining the split file using HJSplit
You can also convert a video file into a .001 file by using split option in HJSplit. You need to provide the size you want to split the file. It will automatically divide the video file into multiple equal halves. The file will be named with .001, .002 and so on. There are many such tools in internet but joining in HJSplit is simple and straightforward than other tools.
In this article I mentioned that .001 is split video file. In real world it can be any file. For example, you can even split a Microsoft Word document if your word document exceeds maximum allowable attachment size. However most of the time it will be a video file. Feel free to comment if you face any issues in the process of joining .001 file using HJSplit.
Read Review of VSDC Free Video Editor from VisualSoftDev
Thanks a ton for this exclusive help. I have a bunch of such broken files which cannot be played on the device. Your article has helped me a lot in getting them to work. I wish this article should have come a bit before - I deleted a few of such unplayable clips!