Whether to edit an EPUB book manually depends on your requirements and experience. If you need complete control over the content and appearance of your book and you are familiar with HTML and CSS, then editing an EPUB book manually may be the best option for you. However, if you are not familiar with HTML and CSS or you do not have the time to edit an EPUB book manually, then you may want to use an EPUB editor. One may need to know various facts when editing an EPUB manually which will be mentioned in the thread.
Make a backup of the original EPUB file before you start editing
It is important to make a backup of the original EPUB file before you start editing. This is because it is possible to make mistakes when editing EPUB files, and it can be difficult to fix these mistakes if you do not have a backup of the original file. There are a few different ways to make a backup of an EPUB file. One way is to simply copy the file to a different location on your computer. Another way is to create a zip archive of the file. This will create a single file that contains all of the files in the EPUB file. Once you have made a backup of the EPUB file, you can start editing it. If you make a mistake, you can simply restore the original file from your backup.
Use a text editor that supports syntax highlighting for XHTML.
it is recommended to use a text editor that supports syntax highlighting for XHTML when editing EPUB files. Syntax highlighting makes it easier to read and edit the HTML and CSS files, as it helps to identify different elements of the code, such as tags, attributes, and values. Some popular text editors that support syntax highlighting for XHTML include Sublime Text, Atom, Visual Studio Code, Brackets, and Notepad++. These text editors also offer a variety of other features that can help edit EPUB files, such as auto-completion, error checking, and code folding. If you are not sure which text editor to use, I recommend trying out a few different ones to see which one you like best. There are many free and open-source text editors available, so you can experiment without having to spend any money.
Unzip the EPUB file
To edit EPUB books manually, you will need to unzip the EPUB file and edit the individual files inside. EPUB files are essentially zip files containing XHTML text files, images, and other resources. To unzip an EPUB file, you can use a variety of tools, such as WinZip, 7-Zip, or the built-in archive tool on your operating system. Once you have unzipped the EPUB file, you will see a folder containing several different files. The main files that you will need to edit are the XHTML files. These files contain the text of your ebook.
Edit the HTML and CSS files
You can edit the XHTML files using any text editor, such as Notepad, Sublime Text, or Visual Studio Code. When editing the XHTML files, be sure to use the XHTML syntax. XHTML is a variant of HTML that is designed for use in ebooks. XHTML syntax is stricter than HTML syntax, so it is important to make sure that your XHTML files are valid. Validate your XHTML files before you zip them back up into an EPUB file. This will help to ensure that your EPUB file is still valid and will be displayed correctly on e-readers. There are several different ways to validate your XHTML files. One way is to use a web browser such as Chrome or Firefox. These browsers have built-in tools that can be used to validate XHTML files. Another way to validate your XHTML files is to use a stand-alone validator such as the W3C Markup Validation Service. This service allows you to validate your XHTML files by uploading them to the service or by providing the URL of the XHTML files.
Repackage the EPUB file
Once you have edited the XHTML files, you will need to zip them back up into an EPUB file. To do this, you can use a variety of tools, such as WinZip, 7-Zip, or the built-in archive tool on your operating system. Test your EPUB file on different devices to make sure that it displays correctly. This is because different e-readers and smartphones use different software and hardware, and this can affect the way that EPUB files are displayed. If you find any problems with the way your EPUB file is displayed on a particular device, you can try editing the EPUB file to fix the problems. You can also contact the manufacturer of the device for support.
However, If you are not comfortable editing EPUB books manually, several software tools can help you to edit EPUB books. Some popular EPUB editing tools include Calibre, Sigil, Vellum, and Adobe InDesign among others.