FAX to SIX Converter

Quick FAX to SIX conversion — no signup needed

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Fax to Digital

Bridge the gap between legacy FAX encoding and SIX — preserve and modernize your fax document archive.

Privacy Guaranteed

FAX uploads are erased upon completion. SIX results are automatically purged from servers within 24 hours.

Simple Workflow

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

How to convert FAX to SIX

1

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

2

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

3

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

About formats

FAX is a generic image file extension associated with facsimile transmission formats standardized by the ITU-T (formerly CCITT), with the underlying Group 3 compression standard ratified in 1980. FAX files typically contain monochrome (1-bit, black and white) image data compressed using the Modified Huffman (MH) encoding defined in ITU-T Recommendation T.4, which assigns variable-length codes to run lengths of consecutive white or black pixels along each scanline. The standard resolution for Group 3 fax is 204x98 dpi (normal mode) or 204x196 dpi (fine mode), reflecting the capabilities of thermal and laser fax machines of the era. FAX files encountered digitally are often raw Group 3 encoded bitstreams or TIFF wrappers with CCITT Group 3 compression (TIFF compression tag 3). The Group 3 encoding scheme is highly efficient for typical business documents — pages with mostly white space and black text — achieving compression ratios of 10:1 to 20:1 compared to uncompressed bitmaps. One advantage is universal fax system compatibility: Group 3 encoding is the mandatory baseline for all fax machines worldwide, meaning FAX files contain data in exactly the format transmitted over telephone lines, preserving the original fax data without transcoding losses. The format's role in business communications history provides another dimension — billions of fax transmissions using this encoding moved legal documents, medical records, and business correspondence for decades, and archived FAX files represent an important documentary record. FAX images can be viewed and converted using LibreOffice, ImageMagick, GIMP, and standard document management systems.
Developer: ITU-T
Initial release: 1980
SIX is a file extension for SIXEL (Six Pixel) graphics data, a bitmap graphics format developed by Digital Equipment Corporation (DEC) in 1983 and introduced with the LA50 dot matrix printer. SIXEL encodes images as a sequence of printable ASCII characters, where each character represents a column of six vertical pixels (a 'sixel') — the character's ASCII value minus 63 provides a 6-bit binary pattern, with each bit controlling one pixel in the vertical column. The encoding is structured as a series of sixel bands (each six pixels tall) across the image width, with control sequences for color selection (up to 256 registers with HLS or RGB specification), repeat counts (run-length encoding for efficiency), carriage return, and newline commands. SIXEL data is transmitted to the output device using DEC's standard escape sequence protocol, embedded within the text stream alongside regular character output. Originally designed for DEC's line of printers and later supported by DEC VT-series terminals (VT240, VT330, VT340), SIXEL has experienced a remarkable revival in modern terminal emulator software. One advantage is terminal-native image display: SIXEL allows images to be rendered directly within a text terminal session without requiring a graphical window system, enabling command-line tools to display graphs, photographs, and previews inline with text output. This capability has driven adoption in modern terminals like mlterm, xterm, WezTerm, and foot. SIX/SIXEL data can be generated by ImageMagick, libsixel, and chafa, and viewed in any SIXEL-capable terminal emulator.
Initial release: 1983

Frequently Asked Questions

Why convert FAX to SIX?

FAX files require specialized fax viewers. Converting to SIX lets anyone open the content easily.

Where can I open SIX files?

Use terminal emulators with Sixel support like xterm or mlterm to view SIX files.

Is fidelity maintained in FAX to SIX conversion?

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

Is FAX to SIX free on Convertio?

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

Can I convert several FAX files simultaneously?

Batch mode is fully supported. Add multiple FAX files and download each converted SIX file individually.

Are my uploaded files kept private?

Absolutely. Uploaded FAX files are deleted after conversion and SIX results are purged within 24 hours.