free · in-browser · no upload
Drop your EPUB file. We'll convert it to HTML right here in your browser, your file never leaves your device.
Select your file here to get started
or drop your file here.
Accepts .epub
How it works
Click the dropzone above or drag a EPUB from your desktop. Files of any size, there's no upload, so there's no upload limit.
The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.
Get your HTML the moment the conversion finishes. Convert another, or close the tab.
Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.
Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.
No account required. No watermark on the output. No queue. Drop a file, get a converted file.
Formats involved
EPUB is the open-standard ebook format used by every major reader except Kindle. Files are zips containing reflowable HTML, CSS, and metadata, text adapts to any screen size. EPUB 3 added audio, video, and interactive elements but most ebooks still ship as EPUB 2 for compatibility.
How to open
Apple Books, Calibre, Adobe Digital Editions, Google Play Books, Kobo readers, Nook, most e-readers except Kindle.
HTML is the markup language of the web, every browser displays HTML documents natively. Files contain text plus tags (<h1>, <p>, <a>, etc.) describing structure and links. Modern HTML5 also supports embedded media (audio/video) and complex semantic markup.
How to open
Every web browser. Any text editor for source. Modern editors (VS Code) syntax-highlight HTML.
Related tools
How we compare
| Feature | Ustwineconvert | CloudConvert | iLovePDF | FreeConvert | Smallpdf |
|---|---|---|---|---|---|
| Files uploaded to a server | |||||
| Free file size limit | No limit | 1 GB | 200 MB | 1 GB | 5 GB |
| Free conversions per day | Unlimited | 10/day | Limited | Limited | 2/day |
| Signup required | |||||
| Watermark on output | |||||
| Works offline (after first load) |
Last verified May 2026 from each competitor's pricing and FAQ pages. Limits and pricing change frequently.
FAQ
Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.
Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.
Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.
Ebooks across non-Kindle readers. Web pages; structured document interchange; readable archives. The most common reason to convert is compatibility, HTML works in places where EPUB doesn't, or vice versa.
Apple Books, Calibre, Adobe Digital Editions, Google Play Books, Kobo readers, Nook, most e-readers except Kindle.
Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.
Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.