RunConvert

RB to OEB Converter

Convert RB to OEB online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

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How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is an RB file?

The RB file format is a proprietary eBook container developed by Nuvo Media for the Rocket eBook, a pioneering dedicated e-reader device released in 1998. The format encapsulates HTML-based content and raster images within a binary structure, often employing a proprietary DRM (Digital Rights Management) encryption scheme. It relies on a pseudo-HTML markup designed specifically for rendering on the monochrome low-resolution displays of early handheld devices.

How to open an RB file

Native support for RB files is absent in modern Windows, macOS, and Linux kernels. Users must utilize specialized eBook management software to parse the legacy binary structure. Calibre is the primary open-source utility recommended for decoding RB containers and converting them to modern standards like EPUB. Alternatively, the legacy RocketLibrarian application can be used in emulated environments.

rb Technical Info

Full Name
Rocket eBook File
Developed By
Nuvo Media
Initial Release
1998
MIME Type
application/x-rocket-ebook

What is an OEB file?

The Open eBook (OEB) format, formally defined by the Open eBook Publication Structure (OEBPS) specification, is a legacy XML-based standard developed by the Open eBook Forum (now IDPF) in 1999. It acts as a manifest file (typically with an .opf extension) that references a package of HTML or XHTML content, CSS stylesheets, and Dublin Core metadata. As the immediate predecessor to the modern EPUB standard, OEB established the structural protocols for separating content from presentation in digital publishing.

How to open an OEB file

OEB files are not natively executable on standard operating systems. To view the content properly assembled, users must utilize dedicated eBook software such as Calibre, which parses the OEBPS manifest to display the book. While the underlying XML and HTML components can be viewed in standard text editors like Notepad++ or Visual Studio Code, this does not render the formatted eBook experience.

OEB Technical Info

Full Name
Open eBook Publication Structure
Developed By
Open eBook Forum
Initial Release
1999
MIME Type
application/x-oeb1-document

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert RB to OEB in seconds

Every RB to OEB conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert RB to OEB via API

Automate RB to OEB conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "rb-to-oeb",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "oeb"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.rb

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.