The CHM file format and its associated .chm filename extension, is a proprietary file format developed by Microsoft. Its full name is compiled HTML Help. CHM was released to the public in 1997 as a bundle with Microsoft Windows 98 and was primarily designed to facilitate documentation on the Windows platform, particularly help files for software applications that run on the Microsoft Windows platform. Essentially, a CHM file is a collection of HTML files packed as a single compressed file. Though the format is proprietary, it was successfully reverse engineered by the late 90's to early 2000s allowing the development of open source readers that are capable of opening files with the .chm extension. The format was succeeded by the LIT format.
The LRF format is a proprietary format developed by Sony in collaboration with Canon, as a document and text encoding standard for the Broad Band eBook file format. The format specifically targeted Sony portable eBook readers and was capable of encoding both text, pagination, and images. Being unencrypted, LRF encoded files do not enforce DRM. This is in contrast to the LRX format which is also part of the BBeB eBook file format which does support encryption for DRM files. The Sony eBook store announced in July 2010 a discontinuation of support for the LRF format in favor of the public and open EPUB format.
FreeFileConvert uses tuned encoding for CHM to LRF conversions, preserving clarity while trimming file size. Finished audio streams instantly across phones, tablets, desktops, and modern browsers without extra tweaks.
Upload CHM files from desktop, tablet, or cloud storage, queue multiple jobs, and let the converter finish autonomously. Return whenever convenient to download synchronized LRF results on any device you rely on.
Process up to 5 files sized 1000 MB per batch without splitting queues manually. Mixed-format uploads convert together, producing consistent LRF audio with dependable progress tracking.
The CHM file format is a binary format that uses the LZX algorithm to compress the HTML data found in the file. The format supports full text searching, indexing, and table of contents, among other useful features.
The LRF format is an XML derivative. It represents the compiled and compressed binary format of the BBeB file. The structure of an .lrf file included a header, an object stream, and an object index. Though the LRF format is a proprietary asset, many freely available programs are able to convert and or open LRF files for viewing.
Upload your document file in the CHM format from your device, Dropbox, or Google Drive.
Select LRF as the output format and click Convert. Adjust optional settings if needed.
Download the converted ebook file. Each file stays available for up to 5 downloads.