Use the Internet to access an online audio compressor website, such as Monkey's Audio, free-codecs and Gary's Hood.
Click on "Browse" to locate the file you want to convert. Select it and click "Open."
Change the bitrate according to how much you want to reduce the file. The lower the bit rate, the smaller the file. The smaller the file, the more sound quality is reduced.
Select an output format and click "Send File." A new page loads when sending is completed.
Right-click the link to your file, and select "Save Target As" or "Save Link As," select an output destination, and click "Save."