RB to MOBI Converter

Convert Rocket eBook to MOBI — free and instant

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Kindle Compatibility

Convert your old RB Rocket eBook files into MOBI — the format Kindle devices and many mobile readers handle natively.

Remote Processing

Conversions run entirely on Convertio cloud servers. Your computer stays idle while the RB file is transformed.

Read Anywhere

MOBI opens on Kindle e-readers, tablets, phones, and desktops — your rescued ebook goes wherever you do.

How to convert RB to MOBI

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose mobi or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your mobi file right afterwards

About formats

RB is the native ebook format of the Rocket eBook, one of the first commercially available dedicated e-reading devices, developed by NuvoMedia and released in October 1998. Founded by Martin Eberhard and Marc Tarpenning — who later co-founded Tesla Motors — NuvoMedia designed the Rocket eBook as a handheld device with a reflective LCD screen, capable of storing approximately ten books in its internal memory. The RB format packages HTML-based content along with embedded images, metadata, and a table of contents into a single binary container optimized for the device's limited hardware. Content was purchased and downloaded through NuvoMedia's RocketLibrarian desktop software. A notable advantage of the format was its early support for bookmarking, annotation, dictionary lookups, and adjustable font sizing — features now standard on modern e-readers but revolutionary in the late 1990s. The Rocket eBook demonstrated viable commercial demand for dedicated reading devices, paving the way for subsequent platforms from Sony, Amazon, and others. NuvoMedia was acquired by Gemstar-TV Guide International in 2000, which discontinued the device line in 2003. While RB files are largely a historical curiosity today, they can be converted to modern formats using ebook management tools, and the format remains significant as a pioneering chapter in the evolution of digital reading.
Developer: NuvoMedia
Initial release: 1998
MOBI is an ebook format originally developed by Mobipocket SA, a French company founded in 2000 that was later acquired by Amazon in 2005. The format builds on the PalmDOC/PDB container structure, adding support for HTML-based content markup, embedded images, a DRM layer, and a JavaScript subset for limited interactivity. MOBI files use a record-based database architecture inherited from Palm OS, with a header structure containing metadata like title, author, publisher, and language followed by compressed HTML content records. The format became the foundation of Amazon's early Kindle ecosystem — the original AZW format used on first-generation Kindles was essentially MOBI with Amazon's own DRM wrapper. MOBI supports reflowable text with basic formatting including bold, italic, headings, lists, and tables, as well as internal hyperlinks and a built-in table of contents. One advantage is broad device compatibility: MOBI files are recognized by Kindle devices and apps spanning over a decade of hardware, as well as numerous third-party readers on desktop and mobile platforms. The format's lightweight structure is another strength — even long novels produce compact files that load quickly on modest hardware. While Amazon has since moved to the more capable AZW3/KF8 format for new publishing, MOBI remains widely circulated in existing ebook libraries and continues to be produced by conversion tools like Calibre for maximum Kindle compatibility.
Developer: Mobipocket SA
Initial release: 2000

Frequently Asked Questions

Why convert RB to MOBI?

RB is an obsolete 1998 ebook format. MOBI is recognized by Kindle devices, Calibre, and many mobile readers — it's far more usable.

What reads MOBI files?

Kindle e-readers and the Kindle app on iOS and Android open MOBI files. Calibre, FBReader, and Moon+ Reader also support it.

Will my book text be accurate after conversion?

Yes, all text content from the RB file is faithfully extracted and placed into the MOBI output with paragraph structure intact.

Can I send the MOBI file to my Kindle?

Yes, transfer via USB or use the Send to Kindle feature. MOBI is natively compatible with all Kindle hardware.

Is RB to MOBI conversion free?

Yes, Convertio converts RB to MOBI at no charge. Premium accounts are available for larger files and batch operations.

RB to MOBI Quality Rating

5.0 (4 votes)
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