A few free all-in-one online format conversion tools

Many times we need to convert files between different formats, such as converting doc to pdf, rmvb to 3gp, etc. These tasks need to be completed through conversion software. In most cases, these softwares are either not all-inclusive, or they come with a fee. Are there any tools that are free, do not require installation, and support multiple formats? Yes! Online services have many advantages, sometimes online conversion is faster than downloading a conversion tool. This article introduces 3 free, all-inclusive online format conversion tools. These 3 services almost support all file formats.