G4 to PDB Converter

Digitize G4 files to PDB — free online converter

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Secure Processing

Source G4 files are deleted instantly after conversion. PDB output files are auto-removed within 24 hours.

Multiple Files

Process several G4 files in a single session. Each produces a separate PDB file for individual download.

Legacy Format Bridge

G4 is a legacy format. Converting to PDB brings your fax archives into modern, widely accessible formats.

How to convert G4 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

G4 is a monochrome image format based on the ITU-T Group 4 facsimile coding standard (Recommendation T.6), ratified by the CCITT in 1984 as an improvement over Group 3 for use on error-free digital networks like ISDN rather than analog telephone lines. G4 files contain 1-bit image data compressed using exclusively two-dimensional Modified Modified READ (MMR) coding, where each scanline is encoded as a set of differences (changing elements) relative to the line above it. By eliminating the one-dimensional coding fallback and the end-of-line synchronization markers required by Group 3, G4 achieves 20-50% better compression ratios on typical document pages while producing a simpler, more regular bitstream. The format is most commonly encountered as a compression method within TIFF files (TIFF compression tag 4), where it became the standard archival format for scanned documents in enterprise document management, government records, and legal imaging systems. G4 compression is specified at 200, 300, or 400 dpi depending on the scanning application, with 300 dpi being the most common for archival-quality document imaging. One advantage is exceptional compression efficiency for document content: G4's two-dimensional prediction exploits the strong vertical correlation in text and line art pages, typically compressing a 300 dpi letter-size page to 30-50 KB — roughly half the size of equivalent Group 3 encoding. The format's entrenchment in document management infrastructure is another strength — G4 TIFF is the mandated format for many government digital records systems, court filing systems, and corporate archives, supported by every enterprise imaging platform.
Developer: ITU-T (CCITT)
Initial release: 1984
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 G4 to PDB?

PDB is widely supported by image viewers and browsers — converting from G4 eliminates the need for fax tools.

Which viewers support PDB?

Open PDB files using Palm OS applications or ImageMagick.

Will the PDB result match G4 quality?

G4 to PDB conversion is lossless for document content. Lines, text, and graphics all remain intact.

Does converting G4 to PDB cost money?

No — standard conversions cost nothing. Premium plans offer higher limits for power users.

Does the converter accept multiple uploads?

Yes — the converter handles multiple files per session. Each G4 upload converts to PDB on its own.

Do I need to create an account?

No registration is needed for standard conversions. Upload your G4 file, convert, and download the PDB result.