G3 to XBM Converter

Quick G3 to XBM conversion — no signup needed

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Fax Content Access

Make G3 content viewable in XBM format — no fax machines or specialized legacy viewers required.

Privacy Guaranteed

G3 uploads are erased upon completion. XBM results are automatically purged from servers within 24 hours.

Simple Workflow

Upload G3, choose XBM, download. Three simple steps — the entire process completes in under a minute.

How to convert G3 to XBM

1

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

2

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

3

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

About formats

G3 is a monochrome image format based on the ITU-T Group 3 facsimile coding standard (Recommendation T.4), ratified by the CCITT in 1980 as the universal compression method for fax transmission over telephone networks. G3 files contain 1-bit (black and white) image data encoded using Modified Huffman (MH) one-dimensional coding, where each scanline is independently compressed by replacing runs of consecutive white or black pixels with variable-length codewords from a predefined Huffman table optimized for typical document content. The standard also defines an optional two-dimensional coding mode (Modified READ) that encodes each line as differences from the previous line, achieving better compression for pages with vertical redundancy. Standard G3 resolution is 204 pixels per inch horizontally and either 98 (standard) or 196 (fine) pixels per inch vertically, producing the characteristic slightly-stretched appearance of received fax documents. The encoding was carefully optimized for the real-time transmission constraints of 1980s modems operating at 2400 to 14400 bps, where encoding and decoding speed had to match the communication channel rate. One advantage is universal telecommunications compatibility: Group 3 encoding remains the mandatory baseline codec for every fax machine manufactured, ensuring that G3 image data can be transmitted to or received from any fax device worldwide. The format's efficiency for document content is another strength — the Huffman tables were statistically tuned to the run-length distributions found in business documents, and typical pages compress to under 30 KB. G3 files are supported by LibreOffice, ImageMagick, and fax server software.
Developer: ITU-T (CCITT)
Initial release: 1980
XBM (X BitMap) is a monochrome (1-bit) image format defined as part of the X Window System, originating at MIT around 1987. XBM files are unique among image formats in being valid C source code: each file defines the image as a static array of unsigned char values containing the packed pixel data, preceded by #define statements specifying the image width, height, and optional hot-spot coordinates (for cursor images). The pixel data is stored in hexadecimal byte values within curly braces, with each bit representing one pixel (1 = foreground, 0 = background) and bits ordered LSB-first within each byte. This design was intentional — XBM images could be #included directly into X Window application source code and compiled into the binary, eliminating the need for external file loading and runtime format parsing. The format was used throughout the X11 ecosystem for cursor shapes, window icons, toolbar buttons, and other small UI elements. One advantage is the source-code nature of the format: XBM files can be edited with a text editor, diff'd and merged in version control, generated by shell scripts, and compiled directly into C programs without any image loading library — a level of toolchain integration that no binary image format can match. The format's role as part of the X Window standard ensures it is understood by every X11-aware toolkit and application. While limited to monochrome and no compression, XBM's simplicity makes it an excellent teaching format for understanding bitmap representations. XBM files are supported by all X11 applications, ImageMagick, GIMP, web browsers (as a legacy web format), and programming environments.
Developer: MIT X Consortium
Initial release: 1987

Frequently Asked Questions

Why convert G3 to XBM?

G3 files require specialized fax viewers. Converting to XBM lets anyone open the content easily.

Where can I open XBM files?

Use text editors (it is plain text), GIMP, or X Window applications to view XBM files.

Is fidelity maintained in G3 to XBM conversion?

Yes — the converter reproduces your G3 content in XBM at full fidelity. No visible quality is lost.

Is G3 to XBM free on Convertio?

Yes, basic usage is completely free. Premium plans are available for additional speed and volume.

Can I convert several G3 files simultaneously?

Batch mode is fully supported. Add multiple G3 files and download each converted XBM file individually.

Do I need to install any software?

No installations needed. The G3 to XBM conversion runs entirely in your browser — nothing to download or set up.