Into the previous article i have mentioned a way to convert or extract the compressed files online but the service was not free as it charges a nominal amount for their expanses etc.

But in case if you are solely looking for a free way to convert the compressed extension like ZIP, RAR, TAR, TGZ, GZIP then 7 Zip archiver can be the best solution. This is free open source application and is capable of handling almost every compression method. It supports creation and extraction of file with archive formats like: 7z, ZIP, GZIP, BZIP2 and TAR. While extraction of content archive formats include: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR etc.

It has simple and easy to use interface that allows easy extraction of content from any archive file. You can also pack and create archive files with ease. Download 7-Zip archiver