To edit XLIFF files, you could use an advanced text editor (such as Sublime Text or Notepad++), any IDE software (such as VisualStudio Code and others), or just use Localazy, which was made specifically with translation file formats in mind. Localazy offers a clutter-free way to browse, edit and manage localization files of many formats.
To open and edit XLIFF files using the Localazy interface, sign up, create a new translation project and upload the XLIFF file. Then head to the File management tab to open the file you just uploaded. You’ll then be able to browse and edit the content of the file in a user-friendly environment.