PDF to EPUB questions
The whole thing rests on people believing the privacy claim, and that only works if the explanations stand up. If something here reads as evasive, it needs rewriting.
Is my PDF uploaded anywhere?
No. The converter is JavaScript running in your browser. It reads the file off your own disk and never sends it anywhere. Don't take our word for it: open devtools, watch the Network tab, and convert something. The first time, the converter's own code loads from this site; after that, nothing goes out at all while it works. (Opening the page loads an analytics beacon, which runs before you pick a file and never sees it.)
Why EPUB and not MOBI or AZW3?
Send to Kindle stopped taking MOBI on 20 December 2023, and it handles EPUB directly, converting it on their end. So EPUB is what you want. It is also the only ebook format a browser can build properly: AZW3 and MOBI are Amazon container formats with no usable JavaScript writer, so any site offering them is running Calibre on a server, which means uploading your file.
Will it work on a scanned book?
No, and it can't. A scan is just photographs of pages, so there's no text in the file to pull out. You'd need OCR software first. We check for this before you convert and tell you, rather than handing you 300 blank pages.
How good is the result?
Good on ordinary prose. Novels, reports, papers and manuals come out reflowable with chapters that work. It struggles with heavy layout: magazines, wide tables, sheet music, equation-dense maths. A reflowable ebook has no fixed page, so anything that depends on where things sit is going to suffer.
Is there a file size limit?
Around 300 MB in practice. The whole document sits in your browser tab while it converts, so a big one can run the tab out of memory. Most books are a few megabytes, so this rarely comes up.
Do you keep the converted EPUB?
We've got nowhere to keep it. The file is assembled in memory and handed to your browser as a download. Close the tab and it's gone.
Does it work offline?
Yes, once you've converted one file. The converter's code downloads the first time you use it, rather than making every visitor fetch it up front, and after that your browser keeps a copy. Pull the plug and convert away.
Can I convert a book I do not own?
That's between you and whoever holds the copyright. We're a format converter and we never see your file, but converting something you have no right to copy is still infringement. Stick to what you're entitled to.
Wondering how it manages all this in a browser?
Have a read →