Free · Private · In your browser
MOBI Reader
Open an old Kindle MOBI (or AZW3) and start reading straight away, right in your browser. Nothing is uploaded, ever.
Files never uploaded Works offline Free, no signup No file size limits
How it works
- Drop your MOBI or AZW3 book into the box above.
- It opens instantly, rendered right here in your browser – no upload, because nothing is sent anywhere.
- Read with adjustable text size and a chapter list. Close the tab and nothing is left behind.
Why “no upload” matters
Every conventional converter site works the same way: your file travels to their server, sits in their queue, gets converted on their hardware, and – you hope – gets deleted afterwards. You can’t verify any of it. The FBI has even warned about free converter sites that use that upload as a way to deliver malware or harvest the documents themselves. Your books are yours; a format change shouldn’t require handing them to a stranger.
ebook.tools removes the question entirely. The converter is delivered to your browser as code and runs on your machine; the file you drop is opened from memory, transformed, and saved back – the network isn’t involved at all. That isn’t a policy promise, it’s an architecture, and you can test it: load this page, switch off your wifi, and convert. It works exactly the same, because there was never anything to send.
A private Kindle reader that keeps your books on your device
MOBI is the old Kindle format, the one your early purchases and years of sideloaded books were saved in before Amazon moved on. Plenty of modern apps no longer open it cleanly, so a private way to just read a .mobi on any device still matters. This reader opens the file entirely on your own machine, the same way every tool on ebook.tools works, so your book is never uploaded to anyone.
Opening a book here unpacks the MOBI, reads its structure and table of contents, and shows one chapter at a time with a contents list you can jump around in. Text resizes to whatever is comfortable, the layout reflows to your screen, and it respects your system’s light or dark theme. The same page opens AZW3 too, so a newer .azw3 download works without converting first.
There is a real security story here, and it is a feature rather than fine print. A Kindle book is a bundle of HTML, and HTML can carry scripts, tracking pixels and links that quietly phone home. Each chapter renders inside a locked-down sandbox with no scripting and no network access at all: images and styles from inside the book are inlined so they display, while anything that would reach the internet is stripped out. A book cannot run code or leak that you opened it.
Two honest limits. DRM-protected store purchases cannot be opened: we detect them and say so, rather than failing silently. And if you would rather keep a universal copy, the MOBI to EPUB converter turns your file into an EPUB you can open anywhere, including our own EPUB reader. Reading modern Kindle files instead? The AZW3 reader is right here.