RunConvert

PDB to MOBI Converter

Convert PDB to MOBI 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

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 a PDB file?

In the context of eBooks, the PDB (Palm Database) format is a sequential record-based container originally engineered for the Palm OS platform. The file structure consists of a fixed-length header containing metadata (such as Type and Creator IDs) followed by a list of record offsets and the raw data records. For digital reading, these records typically contain text compressed via the PalmDOC (LZ77) or zTXT algorithms, effectively acting as a wrapper for eReader content.

How to open a PDB file

Modern desktop operating systems do not include native handlers for Palm OS databases. Users looking to access eBook content within PDB files should use Calibre or STDU Viewer, which can interpret the specific PalmDOC compression. Note that PDB is also an extension for 'Program Database' debug files in Visual Studio; these are binary disparate and require Microsoft development tools, not eBook readers.

PDB Technical Info

Full Name
Palm Database
Developed By
Palm, Inc.
Initial Release
1996
MIME Type
application/vnd.palm

What is a MOBI file?

The Mobipocket eBook format (MOBI) is a binary distribution format developed by Mobipocket SA in 2000, utilizing the Open eBook (OEB) standard and XHTML for reflowable content layout. Encapsulated within a Palm Database (PDB) container, MOBI files employ either the LZ77-based PalmDOC compression or the proprietary HUFF/CDIC algorithm to minimize file size. The format supports Digital Rights Management (DRM), metadata indexing, and javascript capabilities, serving as the foundational architecture for Amazon's proprietary AZW format before the adoption of KF8.

How to open a MOBI file

Native support for MOBI is restricted primarily to Amazon Kindle hardware and legacy Mobipocket readers. On Windows, macOS, and Linux, users require third-party eBook management software such as Calibre, which offers comprehensive viewing and conversion capabilities. Alternatively, the Kindle Previewer tool provided by Amazon or multi-format readers like FBReader and Sumatra PDF can render the unencrypted content of these archives.

MOBI Technical Info

Full Name
Mobipocket eBook Format
Developed By
Mobipocket SA
Initial Release
2000
MIME Type
application/x-mobipocket-ebook

Why RunConvert

The fastest way to convert any file

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

Convert PDB to MOBI in seconds

Every PDB to MOBI 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 PDB to MOBI via API

Automate PDB to MOBI 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": "pdb-to-mobi",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "mobi"
      },
      "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.pdb

# 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.