SK to LRF Converter

Free SK to LRF conversion — Sony Reader eBook format

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Sony Reader Format

LRF was built for Sony Reader devices. Convert SK artwork to LRF for compatibility with the Sony eBook ecosystem.

Web-Based Tool

No Sony eBook software or Skencil needed. Upload your SK file in the browser and receive LRF output immediately.

Cloud-Driven

Conversion runs on Convertio servers. Your device stays free while the SK to LRF file is generated remotely.

How to convert SK to LRF

1

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

2

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

3

Let the file convert and you can download your lrf 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
LRF is the file format associated with Sony's BBeB (Broadband eBook) specification, jointly developed by Sony and Canon and introduced in 2004 with the Sony Librie EBR-1000EP — the world's first commercial E Ink e-reader. The format supports both reflowable text and fixed-layout page rendering, embedding fonts, images, vector graphics, and metadata within a compact binary container. LRF files use a block-based internal structure with object trees describing page layouts, text streams, image resources, and table of contents navigation. Sony's Reader devices and the companion desktop software (Sony Reader Library) served as the primary ecosystem for LRF content throughout the mid-2000s. A key advantage was its early adoption of high-quality font embedding and text rendering optimized specifically for E Ink displays, delivering a reading experience noticeably superior to many competing formats of the era. The format also supported bookmark synchronization, dictionary lookups, and annotations within the Sony Reader ecosystem. However, Sony officially discontinued BBeB/LRF support in 2010, migrating its Reader platform to the industry-standard EPUB format. Today LRF files are primarily encountered in personal ebook collections from that period and can be converted to modern formats using tools like Calibre. The format remains a historically significant milestone as the native format of the device category that launched the modern e-reader revolution.
Developer: Sony
Initial release: 2004

Frequently Asked Questions

Why convert SK to LRF?

LRF is the Sony BBeB eBook format for Sony Reader devices. Converting SK to LRF creates publications compatible with that ecosystem.

What devices read LRF files?

Sony Reader devices support LRF natively. Calibre can also open and convert LRF files to other eBook formats.

Is LRF still supported?

LRF is a legacy format from Sony. While Sony Readers still read it, newer formats like EPUB have largely replaced LRF.

Does the conversion embed my art?

Yes — your SK artwork is embedded in the LRF file as image content viewable on compatible reading devices.

Is this converter free?

Convertio offers free SK to LRF conversion. Premium plans provide larger file capacity and priority processing.