Turn books into audiobooks on your own PC

Most people arrive with an EPUB or a PDF, and those are the two formats this converter is built around. It also reads DOCX, RTF, TXT, Markdown and HTML files, a web page URL, and text you paste in.

• MP3 audiobook. One file for the whole book or one per chapter, with chapter markers, cover art and book tags embedded.
• WAV. Uncompressed audio, if you want to master or edit the narration yourself.
• MP4 video. A cinematic video with the words on screen in time with the voice, for sharing a chapter as a video.

One honest note: NarrationOS does not export M4B. MP3 with chapter markers carries the same chapters, cover art and tags, plays in any player, and many audiobook apps and media servers read the chapters.

• Import. Drag the EPUB or PDF into your library. NarrationOS extracts the text and detects chapters and headings, and runs OCR on scanned pages.
• Pick a voice. Choose a narrator, or clone one from a voice sample you have the rights to use.
• Render. Narrate chapter by chapter or the whole book at once. Each chapter becomes playable as soon as it finishes.
• Export. Save the MP3 audiobook to your drive and play it anywhere.

Everything runs on your own machine. Once first-run setup is done, no part of the conversion needs an internet connection.

EPUB, clearly, when you have the choice. An EPUB carries its own table of contents and chapter markup, so the audiobook's chapters come straight from the book. The EPUB to audiobook guide covers that path.

A PDF describes a page layout rather than a book, so the text has to be reconstructed: reading order, headings, and the page numbers and running headers that should not be read aloud. Scanned, image-only PDFs need OCR first. NarrationOS handles both, and the PDF to audiobook guide explains what to check before you render.

Online EPUB and PDF converters are quick to try, but they work by uploading your book to someone else's server, and they are often metered by the character, the hour of audio or the month. That adds up fast for a whole novel.

A local converter keeps the book, the voice and the finished audio on your own drive. There is no quota and no cap on book length, and it keeps working with the network switched off. The tradeoff is that your own hardware does the work: a supported GPU (NVIDIA CUDA or AMD ROCm) is much faster, and plain CPU still works, just slower than real time. More on that in the offline text to speech guide.

To be straight with you, free local tools exist too. Open-source projects like Audiblez, abogen and ebook2audiobook convert books on your own machine at no cost if you are comfortable with Python and a command line. NarrationOS is for people who want a real desktop app instead.

A plain converter gives you whatever the model says first. Invented names, places and acronyms are where text-to-speech usually falls apart, and a book is full of them.

NarrationOS puts a narration editor between the book and the export. Click any word, set how it should be said, hear the line auditioned in a real sentence, and the fix applies everywhere that word appears. You can also clone a voice for the narrator. The voices are synthetic, AI-generated speech, and not a substitute for a professional human narrator.

Can I convert EPUB to MP3?

Yes. NarrationOS exports the finished audiobook as an MP3 with chapter markers, cover art and book tags embedded, or as uncompressed WAV if you want to master it yourself. You can export a single chapter or the whole book as one file.

Does it export M4B?

No. NarrationOS does not export M4B. It exports MP3 with embedded chapter markers instead, which carries the same chapters, cover art and tags. Any player can play the file, and many audiobook apps and media servers read the chapter markers.

Is there a free EPUB to audiobook converter?

Yes, several. Free online converters exist, though they often limit length or ask you to upload your book. Free open-source tools such as Audiblez, abogen and ebook2audiobook run on your own machine if you are comfortable with Python and a command line. NarrationOS is a paid, one-time purchase for people who want a desktop app with nothing to assemble by hand and an editor for fixing pronunciation.

Can I convert Kindle books, MOBI or AZW3 files?

Only files without DRM. NarrationOS can open MOBI, AZW, AZW3 and FB2 files if you have the free Calibre app installed, because it converts them to EPUB first. Books bought from a store are usually locked with DRM, and those cannot be converted. EPUB is the best input when you have a choice.

Does the converter work offline?

Yes, after first-run setup. The book is read, narrated and exported entirely on your own PC, so nothing is uploaded and there is no per-character quota or monthly fee.

Can I sell an audiobook I convert?

Yes, if the rights are yours: you need rights to the book text and to any cloned voice. Public-domain books and your own writing are the safest ground. Some audiobook storefronts have their own rules about AI-narrated titles, so check the platform you plan to publish on.

• EPUB to audiobook
• PDF to audiobook
• Offline text to speech
• Voice cloning for audiobooks
• Back to the NarrationOS home page