What software can open RB files?

Legacy software such as the original Rocket eBook Reader or modern conversion tools like Calibre (with specific plugins) are required to open or convert RB files.

Is the RB format still used today?

No, the RB format is considered obsolete and has been replaced by open standards like EPUB and proprietary formats like AZW or KFX.

.rbapplication/x-rocket-ebook

RB (.rb)

RB (Rocket eBook) is a legacy ebook format for the Rocket eBook and REB 1100 e-readers.

Quick Facts

File Extension: .rb
MIME Type: application/x-rocket-ebook
Category: Ebook
Full Name: RB

What is RB?

The RB file format, also known as the Rocket eBook format, was a pioneering digital book standard developed in the late 1990s for the Rocket eBook and REB 1100 e-readers. As one of the earliest proprietary ebook formats, it played a crucial role in the nascent digital publishing industry by allowing users to carry entire libraries on a single handheld device. Although it is now considered a legacy format, its introduction marked a significant shift from physical books to portable digital reading experiences.

Technically, the RB format was designed specifically for the hardware constraints of early e-readers, utilizing a proprietary compression algorithm to optimize text and simple graphics for low-resolution monochrome displays. The format supported basic text reflow and limited formatting options, making it suitable for novels and text-heavy documents but less ideal for complex layouts or multimedia content. Its ecosystem was tightly controlled by NuvoMedia, the original developer, which limited its widespread adoption compared to open standards that emerged later.

Today, the RB format is largely obsolete, with most modern e-readers and software no longer supporting it natively. However, it remains a subject of interest for digital archivists and historians studying the evolution of e-book technology. Converting RB files to modern formats like EPUB or PDF is often necessary for preservation, requiring specialized legacy software or conversion tools to ensure the content remains accessible to contemporary readers.

Technical Specifications

Developer	NuvoMedia
First Released	1998
Type	Proprietary Ebook Format
Compression	Custom Proprietary Compression
Max Resolution	480 x 320 pixels
Color Depth	4-bit Grayscale (16 levels)

Pros & Cons

+Advantages

•Optimized for early low-power e-ink displays
•Compact file size due to efficient compression
•Supported text reflow for better readability on small screens
•Pioneered the concept of portable digital libraries

−Disadvantages

•Proprietary format with limited software support today
•No support for modern multimedia or complex layouts
•Incompatible with most contemporary e-readers
•Requires conversion tools for modern access

Common Use Cases

Archiving historical digital literature from the late 90s

Converting legacy Rocket eBook collections to EPUB

Studying the history of e-reader technology

Restoring old digital manuscripts for academic research

Convert from RB

Convert .rb files to other formats.

.rb.pdf

Convert RB (.rb) files to PDF (.pdf) format. Transform your RB files to PDF quickly and easily with File ConverterX — completely free.

.rb.docx

Convert RB (.rb) files to DOCX (.docx) format. Transform your RB files to DOCX quickly and easily with File ConverterX — completely free.

.rb.epub

Convert RB (.rb) files to EPUB (.epub) format. Transform your RB files to EPUB quickly and easily with File ConverterX — completely free.

.rb.rtf

Convert RB (.rb) files to RTF (.rtf) format. Transform your RB files to RTF quickly and easily with File ConverterX — completely free.

.rb.html

Convert RB (.rb) files to HTML (.html) format. Transform your RB files to HTML quickly and easily with File ConverterX — completely free.

.rb.txt

Convert RB (.rb) files to Plain Text (.txt) format. Transform your RB files to TXT quickly and easily with File ConverterX — completely free.

.rb.mobi

Convert RB (.rb) files to MOBI (.mobi) format. Transform your RB files to MOBI quickly and easily with File ConverterX — completely free.

.rb.azw3

Convert RB (.rb) files to AZW3 (.azw3) format. Transform your RB files to AZW3 quickly and easily with File ConverterX — completely free.

.rb.fb2

Convert RB (.rb) files to FB2 (.fb2) format. Transform your RB files to FB2 quickly and easily with File ConverterX — completely free.

.rb.htmlz

Convert RB (.rb) files to HTMLZ (.htmlz) format. Transform your RB files to HTMLZ quickly and easily with File ConverterX — completely free.

.rb.lit

Convert RB (.rb) files to LIT (.lit) format. Transform your RB files to LIT quickly and easily with File ConverterX — completely free.

.rb.lrf

Convert RB (.rb) files to LRF (.lrf) format. Transform your RB files to LRF quickly and easily with File ConverterX — completely free.

.rb.pdb

Convert RB (.rb) files to PDB (.pdb) format. Transform your RB files to PDB quickly and easily with File ConverterX — completely free.

.rb.pml

Convert RB (.rb) files to PML (.pml) format. Transform your RB files to PML quickly and easily with File ConverterX — completely free.

.rb.snb

Convert RB (.rb) files to SNB (.snb) format. Transform your RB files to SNB quickly and easily with File ConverterX — completely free.

.rb.tcr

Convert RB (.rb) files to TCR (.tcr) format. Transform your RB files to TCR quickly and easily with File ConverterX — completely free.

Convert to RB

Convert other files to .rb format.

.pdf.rb

Convert PDF (.pdf) files to RB (.rb) format. Transform your PDF files to RB quickly and easily with File ConverterX — completely free.

.docx.rb

Convert DOCX (.docx) files to RB (.rb) format. Transform your DOCX files to RB quickly and easily with File ConverterX — completely free.

.epub.rb

Convert EPUB (.epub) files to RB (.rb) format. Transform your EPUB files to RB quickly and easily with File ConverterX — completely free.

.odt.rb

Convert ODT (.odt) files to RB (.rb) format. Transform your ODT files to RB quickly and easily with File ConverterX — completely free.

.rtf.rb

Convert RTF (.rtf) files to RB (.rb) format. Transform your RTF files to RB quickly and easily with File ConverterX — completely free.

.html.rb

Convert HTML (.html) files to RB (.rb) format. Transform your HTML files to RB quickly and easily with File ConverterX — completely free.

.txt.rb

Convert Plain Text (.txt) files to RB (.rb) format. Transform your TXT files to RB quickly and easily with File ConverterX — completely free.

.mobi.rb

Convert MOBI (.mobi) files to RB (.rb) format. Transform your MOBI files to RB quickly and easily with File ConverterX — completely free.

.azw4.rb

Convert AZW4 (.azw4) files to RB (.rb) format. Transform your AZW4 files to RB quickly and easily with File ConverterX — completely free.

.cb7.rb

Convert CB7 (.cb7) files to RB (.rb) format. Transform your CB7 files to RB quickly and easily with File ConverterX — completely free.

.cba.rb

Convert CBA (.cba) files to RB (.rb) format. Transform your CBA files to RB quickly and easily with File ConverterX — completely free.

.cbr.rb

Convert CBR (.cbr) files to RB (.rb) format. Transform your CBR files to RB quickly and easily with File ConverterX — completely free.

.cbt.rb

Convert CBT (.cbt) files to RB (.rb) format. Transform your CBT files to RB quickly and easily with File ConverterX — completely free.

.cbz.rb

Convert CBZ (.cbz) files to RB (.rb) format. Transform your CBZ files to RB quickly and easily with File ConverterX — completely free.

.chm.rb

Convert CHM (.chm) files to RB (.rb) format. Transform your CHM files to RB quickly and easily with File ConverterX — completely free.

.djvu.rb

Convert DjVu (.djvu) files to RB (.rb) format. Transform your DJVU files to RB quickly and easily with File ConverterX — completely free.

.fb2.rb

Convert FB2 (.fb2) files to RB (.rb) format. Transform your FB2 files to RB quickly and easily with File ConverterX — completely free.

.lit.rb

Convert LIT (.lit) files to RB (.rb) format. Transform your LIT files to RB quickly and easily with File ConverterX — completely free.

.lrf.rb

Convert LRF (.lrf) files to RB (.rb) format. Transform your LRF files to RB quickly and easily with File ConverterX — completely free.

.pdb.rb

Convert PDB (.pdb) files to RB (.rb) format. Transform your PDB files to RB quickly and easily with File ConverterX — completely free.

.pml.rb

Convert PML (.pml) files to RB (.rb) format. Transform your PML files to RB quickly and easily with File ConverterX — completely free.

.recipe.rb

Convert Calibre Recipe (.recipe) files to RB (.rb) format. Transform your RECIPE files to RB quickly and easily with File ConverterX — completely free.

.snb.rb

Convert SNB (.snb) files to RB (.rb) format. Transform your SNB files to RB quickly and easily with File ConverterX — completely free.

.tcr.rb

Convert TCR (.tcr) files to RB (.rb) format. Transform your TCR files to RB quickly and easily with File ConverterX — completely free.

Frequently Asked Questions

No, modern e-readers like Kindle and Kobo do not natively support the RB format. You must convert the file to a compatible format like EPUB or PDF first.

Need to convert RB files?

File ConverterX supports converting .rb files to and from dozens of formats — completely free.

Browse Conversions