Direct answer
To read fanfiction offline, first convert the chapters into a portable file. EPUB is the better default for Kindle, Kobo, Apple Books, and other e-readers. Reader Mode HTML is better when you want browser read-aloud tools or a speech app.
Choose the format by the final destination
Choose EPUB if the final destination is an e-reader library. Choose Reader Mode HTML if the final destination is Edge Read Aloud, Safari Listen to Page, or another TTS workflow.
Offline workflow
- Add chapters with URL Fetcher or Manual Entry.
- Export EPUB or Reader Mode HTML.
- Move the file to your reading app or device.
- Keep the exported file locally for later reading or listening.