FAX to SK1 Converter

Online FAX to SK1 converter — quick, free, secure

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

Archive Modernization

Move FAX documents to SK1 format — accessible without specialized fax software or legacy hardware.

Privacy Guaranteed

FAX uploads are erased upon completion. SK1 results are automatically purged from servers within 24 hours.

Batch Processing

Upload multiple FAX files at once. Each converts to SK1 independently — download them all when ready.

How to convert FAX to SK1

1

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

2

Choose sk1 or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your sk1 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
SK1 is the native file format of the sK1 project), an open-source vector graphics editor and conversion engine started by Igor Novikov in 2003 as a successor to Bernhard Herzog's Skencil. The format evolved from the original SK format, extending its capabilities while maintaining the text-based, Python-readable syntax for describing vector documents. SK1 files encode complete document structures including multiple pages, layers, guidelines, and a full hierarchy of graphic objects — Bezier paths, rectangles, circles, polygons, text blocks, and embedded raster images — with attributes for fills (solid, gradient, pattern, hatching), strokes, and transformations. The sK1 project distinguished itself by focusing on prepress and professional print production features, adding CMYK color management, ICC color profiles, spot color support, and PDF/PostScript output — capabilities unusual in open-source vector editors. One advantage is professional color handling — sK1's CMYK workflows and color management make it one of the few open-source tools suitable for print-ready vector production. The project's companion tool, UniConvertor, leverages the SK1 format as an intermediate representation for converting between numerous vector formats (CDR, CMX, WMF, EMF, SVG, and others), giving SK1 significance beyond the editor itself as a universal interchange format. The text-based file structure preserves the readability and scriptability advantages inherited from Skencil's original SK format.
Initial release: 2003

Frequently Asked Questions

Why convert FAX to SK1?

Converting fax images to SK1 vector format allows scaling without quality loss — useful for design and publishing.

What programs handle SK1?

SK1 files can be opened with sK1, Inkscape, or UniConvertor.

Does the SK1 output keep original clarity?

The conversion engine preserves every pixel of the FAX original. Your SK1 output matches the source quality.

Is the FAX to SK1 tool free?

Standard usage is free. Premium plans are available for users who need higher throughput and faster speeds.

Can I upload several FAX files together?

Multiple FAX files can be uploaded together. Each is processed individually and produces its own SK1 output.

Is my data secure during conversion?

Uploaded FAX files are deleted immediately after conversion. SK1 results are automatically removed within 24 hours.