Changing the format of an e-book usually required a professional e-book conversion tool because different e-book format had different requirements for the layout, font, line spacing, header, and footers of the text. The following are some commonly used e-book format and their conversion methods: 1. The Kindle format: The Kindle format is an e-book format introduced by Amazon for Kindle devices and applications. You need to use the KDG software package to convert the e-book to the Kindle format. You need to make sure that you have registered and purchased the Amazon app before switching. 2 MOBi format:MOBi format is an e-book format developed by the company, suitable for mobile devices such as Android and Android devices. You need to use the Android MOBI-translator to convert the file into a MOBI-file. 3. PDF-format: PDF-format is a widely used electronic document format that can be used to create and convert various types of documents. If you need to convert a PDF-file to an e-book format, you can use a PDF-translator such as Android. 4. TMT format: The TMT format is a text file format commonly used to create text documents or e-books. There was no need to convert because all e-book format supported this format. Whichever format you choose, the conversion process may take some time depending on the file size and the performance of the translator. In addition, the converted files may need to be recompressed to accommodate the storage capacity of the mobile device. Therefore, please make sure to consider the required storage space and device type before converting.