OTB to PDB Converter

Convert OTB images to PDB e-book format online

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Effortless Process

Converting OTB to PDB takes just a few clicks — no technical knowledge required. Upload, choose your format, and download the result.

Batch Processing

Upload multiple OTB files at once and convert them all to PDB in a single session — ideal when you have many legacy images to migrate.

Privacy Protected

Your OTB files are deleted immediately after conversion to PDB. Converted files are automatically removed from servers within 24 hours.

How to convert OTB to PDB

1

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

2

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

3

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

About formats

OTB (Over-the-Air Bitmap) is a monochrome image format developed by Nokia as part of their Smart Messaging specification in 1997, designed for transmitting small graphics — operator logos, group graphics, and picture messages — to Nokia mobile phones via SMS. OTB files contain 1-bit (black and white) images at small fixed resolutions, typically 72x14 pixels for operator logos and 72x28 pixels for group graphics, encoded in a compact binary format suitable for embedding within the payload of SMS text messages. The format uses a simple structure: a header byte indicating whether the image is an operator logo or group graphic, width and height values, and the raw bitmap data where each bit represents one pixel packed eight per byte. The extremely tight format — designed to fit within a single SMS message (140 bytes maximum payload, shared with addressing overhead) — reflects the severe constraints of mobile communication in the late 1990s. Nokia's Smart Messaging system was one of the first commercial implementations of rich content delivery to mobile phones, and OTB images represented the entire visual content capability of Nokia handsets before MMS and mobile data browsing arrived. One advantage is the format's historical role as a pioneer of mobile visual messaging: OTB images were among the first graphics that ordinary consumers could send to each other's phones, predating MMS, camera phones, and smartphones by nearly a decade. The format's minimal footprint is another characteristic — entire images fit in a few dozen bytes, reflecting an era of extreme bandwidth constraints. OTB files are supported by ImageMagick, various Nokia phone management tools, and specialty mobile format utilities.
Developer: Nokia
Initial release: 1997
PDB (Palm Database) is a generic database container format created by Palm, Inc. for the Palm OS platform, first appearing with the original PalmPilot in March 1996. In the ebook context, PDB files most commonly use the PalmDOC or Plucker encoding to store readable text with basic formatting. The format consists of a 78-byte header identifying the database name, creation date, and record count, followed by a record index table and the data records themselves. PalmDOC-encoded PDB files use a simple LZ77-based compression scheme to pack plain text efficiently, while Plucker extends this with HTML rendering, image support, and hyperlink navigation. PDB ebooks powered a thriving mobile reading ecosystem years before dedicated e-readers existed — millions of Palm OS users carried entire libraries on devices like the Palm V, Tungsten, and Treo handhelds. A primary advantage is extreme simplicity: the flat record structure and minimal overhead mean PDB files parse instantly even on severely constrained hardware with limited memory and processing power. The open, well-documented structure is another strength, having spawned numerous reader applications across Palm OS, Windows, and later mobile platforms. Though the Palm platform is long discontinued, PDB ebooks remain accessible through conversion tools and readers like Calibre, and the format holds historical significance as one of the earliest practical mobile ebook solutions.
Developer: Palm, Inc.
Initial release: March 1996

Frequently Asked Questions

Why would I convert OTB to PDB?

PDB (data container used on Palm OS devices) lets you include OTB graphics in e-book collections, accessible on dedicated readers and mobile apps.

What apps support PDB?

You can view PDB with Calibre, Palm OS emulators, some e-reader apps. These tools cover all major desktop and mobile platforms.

How long does OTB to PDB conversion take?

Usually just seconds. OTB files are typically small, so the upload, conversion, and download process finishes very quickly on Convertio.

Can I convert multiple OTB files to PDB at once?

Absolutely. Batch upload your OTB images and convert them all to PDB in a single pass — no need to repeat the process for each file.

Is my OTB file safe when converting online?

Your files are secure. Uploaded OTB images are erased immediately after processing, and PDB outputs are purged within 24 hours.