G3F File

What are G3F files and how to open them

Are you having problems opening a G3F file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your G3F files.

What is a G3F file?

A .G3F file is a Zetafax Fax Image File (Fine) file.

A Zetafax Fax Image File (Fine) file is a black-and-white fax image saved by the Zetafax fax server software in its higher resolution ("fine") mode. It is used to store archived copies of sent or received faxes at detail suitable for readable text, detailed line art or logos, and is often used for cover-sheets, letterheads, or attachments within Zetafax when higher quality is required.

The file is produced by Zetafax when a fax is sent or received in fine mode (typically 200 dpi × 200 dpi vertical and horizontal resolution). Zetafax also uses a companion extension (.G3N) for normal mode (lower resolution) images. When graphics-based files, documents or letterheads are prepared for faxing, the user or administrator often prints or saves them in fine mode, and the server renders them into the .G3F format using its built-in TIFF/Group-3 fax image routines.

Technically, a .G3F file is a TIFF image file conforming to Group-3 fax (CCITT T.4) encoding using one-dimensional Modified Huffman (MH) compression. It is stored as a single data strip per page, with 1 bit per pixel, and a scan-line width of 1728 pixels. Autoconversion or strict requirements may apply to ensure all tag values and image dimensions match what Zetafax expects.

How to open G3F files

We have identified one G3F opener that is compatible with this specific type of G3F file.

Programs that open Zetafax Fax Image File (Fine) files

Last updated: August 6, 2026

Various apps that use files with this extension

These apps are known to open certain types of G3F files. Remember, different programs may use G3F files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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