SK to WBMP Converter

Free SK to WBMP conversion — monochrome bitmap output

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Compact Output

WBMP files are extremely small. Convert your SK drawings to WBMP for lightweight monochrome images suitable for constrained devices.

Cloud Conversion

Processing happens entirely on Convertio servers. Upload your SK file and receive WBMP output without taxing your device.

No Software Required

Convert SK to WBMP using only your web browser. No need to install Skencil or any image editing software locally.

How to convert SK to WBMP

1

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

2

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

3

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

About formats

SK is the native file format of Skencil (originally named Sketch), a free vector graphics editor for Linux created by Bernhard Herzog, with the first public release on October 31, 1998. Skencil holds historical significance as one of the earliest full-featured vector drawing applications written almost entirely in Python, with only performance-critical rendering components implemented in C. The SK file format uses a text-based, Python-like syntax to describe document structure — pages, layers, groups, and individual graphic objects are represented as nested statements with parameters specifying coordinates, colors, line styles, and transformations. The format supports Bezier curves, rectangles, ellipses, text objects with font specifications, imported raster images, gradient and pattern fills, and hierarchical grouping with affine transforms. One advantage is human readability — SK files can be opened in any text editor, making it possible to inspect, modify, or generate artwork programmatically using simple scripts. The Python-native structure also provides a benefit for automation: since Skencil itself is a Python application, the file format integrates naturally with scripting workflows for batch processing and procedural graphic generation. While Skencil's development slowed after the mid-2000s, its SK format became the foundation for the sK1 project, which extended the format and continued active open-source vector graphics development. SK files remain convertible through sK1, UniConvertor, and other open-source tools.
Developer: Bernhard Herzog
Initial release: October 31, 1998
WBMP (Wireless Bitmap) is a monochrome (1-bit, black and white) image format defined as part of the Wireless Application Protocol (WAP) specification, developed by the WAP Forum (later consolidated into the Open Mobile Alliance) around 1998. The format was designed for the extremely constrained mobile devices of the late 1990s and early 2000s — phones with small monochrome screens, minimal processing power, and narrow bandwidth GSM data connections. WBMP uses the simplest possible encoding: a type identifier byte (always 0 for the only defined type), width and height encoded as multi-byte integers using a variable-length scheme, and the raw pixel data where each bit represents one pixel (0 for white, 1 for black) packed eight per byte. There is no compression, no metadata, and no color — the format is purely a minimal container for delivering small monochrome graphics to WAP-era mobile browsers. One advantage was extreme efficiency on constrained devices — WBMP images could be decoded with virtually zero CPU overhead and minimal memory, critical on early mobile hardware running at single-digit megahertz clock speeds. The tiny file sizes are another strength: a typical WBMP icon occupied just a few hundred bytes, practical for transfer over 9.6 kbps GSM data channels. While the WAP ecosystem has been entirely superseded by modern mobile web browsers capable of rendering full-color JPEG, PNG, and WebP images, WBMP files remain encountered in archived mobile content from that transitional era.
Developer: WAP Forum
Initial release: 1998

Frequently Asked Questions

Why convert SK to WBMP?

WBMP is a monochrome bitmap format designed for mobile devices. Converting SK to WBMP creates compact images for legacy wireless applications.

What programs handle WBMP files?

GIMP, IrfanView, XnView, and some mobile WAP browsers can open and display WBMP files. ImageMagick also processes them.

Is WBMP just black and white?

Yes — WBMP is a 1-bit monochrome format. Your SK artwork will be rendered as a black-and-white bitmap with no color gradients.

Does the conversion cost anything?

Convertio provides SK to WBMP conversion for free. Premium subscriptions add higher limits and expedited processing.

Can I convert multiple SK files to WBMP at once?

Batch conversion is supported. Upload several SK files simultaneously and each one converts to WBMP independently in a single session.