MOBI to PDB Converter

Convert MOBI to PDB format online — free ebook tool

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Legacy Format Bridge

Bridge the gap between MOBI ebooks and Palm OS devices — the PDB format gives your books new life on vintage hardware.

Browser-Based Tool

No software to install or configure. The entire MOBI to PDB conversion happens in your web browser on any operating system.

Secure Processing

Uploaded MOBI files are purged immediately after conversion. PDB results are cleaned from servers within 24 hours.

How to convert MOBI 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

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
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 convert MOBI to PDB?

PDB is required for Palm OS devices and some legacy PDA readers. Converting from MOBI makes your ebooks readable on these older platforms.

How do I open a PDB file?

Palm OS devices read PDB natively. On modern systems, Calibre can open and convert PDB files, and some older PDA emulators support it too.

Is PDB still used today?

PDB is largely a legacy format, but collectors and enthusiasts maintaining Palm devices still need it. Convertio makes the conversion painless.

Does the conversion keep book metadata?

Basic metadata like title and author transfers from MOBI to PDB. Some advanced metadata fields may not carry over due to format limitations.

Can I batch-convert multiple MOBI ebooks to PDB?

Yes. Upload several files at once on Convertio and convert them all to PDB format in a single batch — efficient for larger collections.

MOBI to PDB Quality Rating

4.7 (323 votes)
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