A file compressor is a program that can be used to compress a single file and reduce the file size on disk or to combine multiple files into a single one (the archive) reducing the size in the same time.
These programs can offer features such as encryption with password, split automatically an archive into multiple parts based on a maximum file size, creation of self-extracting archives that acts as executable file (is still an archive, but with .exe extension), test an archive to find errors or repair corrupted/damaged ones.
Although they are known as file archivers or file compression, in fact there is a difference between archiving and compression. Archive means a collection of files grouped into a single one with no file size reduction, while compression means an archive with file size reduced.
Most popular formats are .zip, .rar, .7z, but also you may deal with archives like .cab, .lzh, .gz, .tar.gz, .zipx.
Working with archives is easy and will make your life easier when you send or transfer multiple files through internet, because will save time working with smaller file sizes.
Also, you will free up hard disk space on computer. Compressing and reducing file size can also reduce your costs if you keep backups of files on cloud services such as Dropbox, Google Drive etc. where extra amount of hard disk space is paid.
We tested different types of files, most common ones on a Windows computer: JPG photos, PDFs, Office documents (doc, docx, xls, xlsx, ppt, pptx), high quality MP3 audio files, popular video formats, executables (software and games).
We created ZIP archives and we extracted from ZIP files, since ZIP is widely supported by all programs and is the most used compression format these days (although isn't the best), to have an unique point of reference. We tested file extraction from each type of archive.
Keep in mind that not only you will work with these files, but also the people who will receive them and need to open and extract the content, in order to use it.
7Z (.7z) is the best format to reduce file size and is supported by all major programs (create and extract). Here you can see our test.
A file compression software should be able to compress and extract files very fast. The speed is important. Also, it needs to support all popular and efficient formats for compression and extraction.
As you can see, file size reduction is similar for all products, because we tested by creating a ZIP archive. But you can reduce the file size if you are using another format - see out test.
We used the following criteria to evaluate the programs:
Compression and Extraction Speed
Save your time working with programs that are able to perform the operations faster than others.
Is important that a file archiver to be able to create .7z archives, because its the best at reducing file size. It is supported by many free and paid programs.
Maybe more important than compression is the support for extraction. You may receive different kind of archives through e-mail, download etc. and you should be able to extract the content without installing another specialized program.
A good archivator allows to protect the file with a password, to customize right click menu with desired menus, test and archive for errors automatically at the end of archiving (you need to send or store valid files), but also to repair damaged archives (just in case).