Free e-book converter with no sign-up and no upload
This e-book converter is free, needs no sign-up or login, and never asks you to upload anything. Your books are opened and converted inside your browser tab, so the files never leave your device. There is no watermark on the result and nothing to install.
Add an EPUB, MOBI, AZW3, FB2 or CBZ file and pick the format your reader, phone or printer needs. EPUB, FB2, PDF, plain text, HTML, Markdown and DOCX are available as targets, and a comic book in CBZ can become an EPUB or a PDF. You can also go the other way: Word, PDF, Markdown, HTML, RTF and text documents can be turned into an EPUB or FB2 for reading on an e-reader.
E-books are not photographs, so the honest question is what survives. Text, headings, links and images are kept, and the chapter structure carries over. Page layout does not: an e-book is reflowable text, and fixed positions, unusual typography and complicated formatting are simplified. If a book is heavy on layout, check the result before you delete the original.
One limit cannot be worked around. Books bought from a store are often protected with DRM, and a DRM-protected MOBI or AZW3 cannot be converted here. The converter works on files you can already open without a licence key.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Drag your e-book files onto the page, or choose them with the file picker.
- Check that each file was recognised as EPUB, MOBI, AZW3, FB2 or CBZ.
- Choose the target format, for example EPUB for a Kindle or Kobo app, or PDF for printing.
- Adjust any options that appear for that format.
- Press Convert and wait while the books are processed on your device.
- Download each result on its own, or take a batch as one ZIP file.
Features
- Reads EPUB, MOBI, AZW3, FB2 and CBZ.
- Writes EPUB, FB2, PDF, TXT, HTML, Markdown and DOCX.
- Turns CBZ comic archives into an EPUB or a PDF, one page image per page.
- Turns Word, PDF, Markdown, HTML, RTF and text documents into EPUB or FB2.
- Keeps text, headings, links and images, and simplifies page layout.
- Batch conversion with a single ZIP download.
- No engine download is needed for e-book conversion.
- Free, with no sign-up, no upload and no watermark.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| PDF.pdf | Yes | Yes | Fixed-layout document format that looks the same on every device. |
| Markdown.md | Yes | Yes | Plain text with light markup for headings, lists, links and emphasis. |
| HTML.html | Yes | Yes | The markup language of web pages. |
| Plain text (TXT).txt | Yes | Yes | Unformatted text with no styles, images or layout. |
| EPUB.epub | Yes | Yes | The open standard for e-books; text reflows to fit any screen size. |
| MOBI.mobi | Yes | No | MOBI is a legacy format superseded by KF8 and EPUB; Kindle accepts EPUB, so MOBI can be read but not created. |
| AZW3 (KF8).azw3 | Yes | No | AZW3 is Amazon’s proprietary format; Kindle accepts EPUB, so AZW3 can be read but not created. |
| FictionBook (FB2).fb2 | Yes | Yes | XML e-book format popular in Russian-speaking countries. |
| Comic book (CBZ).cbz | Yes | Yes | A ZIP archive of page images, read by comic book apps. |
About the formats
About EPUB
EPUB is the open standard for e-books. Its text reflows to fit any screen size, and it is a ZIP of HTML files kept by the W3C, formerly the IDPF.
Almost every e-reader app opens it, and Kindle accepts it through Send to Kindle. That is why EPUB is the most useful target for MOBI and AZW3 books, which can be read here but not written.
About MOBI and AZW3
MOBI is the older Kindle format, based on the Mobipocket reader. AZW3, also called KF8, is Amazon's Kindle Format 8 and the successor of MOBI. Both are read-only here because Kindle now accepts EPUB.
Files bought from Amazon are usually DRM protected, and those cannot be converted. DRM-free books, such as ones you made yourself or downloaded from authors who share them freely, convert normally.
About FB2
FictionBook is an XML format popular in Russian-speaking countries. It describes structure, such as chapters and notes, rather than page layout, so it converts to EPUB with little friction.
About CBZ
A CBZ file is a ZIP archive of page images read by comic book apps. The pages are plain images, so no text can be reflowed. Converting to EPUB or PDF keeps each page image as one page.
Because CBZ holds pictures, a CBZ converted to PDF is only as sharp as the original scans.
EPUB vs PDF
EPUB reflows: the text adapts to a small phone screen or a large tablet and the reader can change the font size. PDF is fixed: every page looks the same everywhere, which suits printing and sharing but is awkward on a small screen.
Convert to EPUB for reading on a device, and to PDF when you need a stable page to print or send.
Privacy: how it works
- Your e-books stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
- A book can say a lot about its reader. Because nothing is sent to a server, your library, reading habits and any personal notes inside a file stay private to your device.
- The converter does not remove DRM and does not try to. A protected book stays protected, and the page will not read it.
Tips
- Pick EPUB as the target if you are unsure. It is the format most reading apps and Kindle accept.
- Open the converted file in your reader and check the table of contents and the first chapter before converting a whole shelf.
- Use TXT or Markdown if you only want the words, for example to paste into notes or a translation tool.
- Convert to PDF only when you need fixed pages. A PDF made from reflowable text will not adapt to your screen.
- For a scanned book saved as a PDF, expect no extractable text. A scan is a picture of a page, and nothing can be read out of it.
- Make a comic readable on a phone by converting CBZ to EPUB, but keep the CBZ if your comic app already opens it.
- Keep the original file. Conversion simplifies layout, and you may want the first version later.
- If a MOBI or AZW3 file will not open at all, it is probably DRM protected and cannot be converted here.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your e-books are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.