how to shrink a file
1 WinRAR-Right-click on the file or folder you want to compress and select Add to archive with the WinRAR logo. 2  Note that increasing compression levels can significantly increase the time it takes to compress. 3  In the General tab, select Best from the Compression method drop-down menu. 7-Zip-Right-click on the file or folder you want to compress and select 7-Zip â Add to archive. 2  In the Add to Archive menu, you can set your compression options. 3  Note that increasing compression levels can significantly increase the time it takes to compress.