Convert Documents to LRF Online — Free Sony eBook Converter
Convert a wide range of document and eBook formats to LRF, the native format for Sony Reader devices, entirely online and free of charge — no software installation or account needed.
What is the LRF format?
LRF (Libre Reader Format) is a proprietary eBook format developed by Sony for use with its Reader line of e-ink devices, including the PRS-500, PRS-505, and PRS-700 series. It stores reflowable text, images, and basic formatting in a compact binary structure optimised for the small, high-contrast screens of early Sony Readers. LRF files typically carry the .lrf extension, while the companion .lrs (LRF Source) format is a human-readable XML variant used as an authoring intermediate.
Although Sony later shifted toward the open EPUB standard, millions of LRF-format titles were distributed through the Sony Reader Store, and a large back-catalogue of LRF content still circulates among Sony Reader owners today.
Why convert to LRF?
Converting your documents or eBooks to LRF is useful whenever you want to read content on a Sony Reader device that does not natively open other formats such as PDF or DOCX. Key reasons to convert include:
- Device compatibility — older Sony Reader models only recognise LRF files; converting ensures full native display without third-party firmware.
- Optimised reflowing — LRF text reflows to fit the screen width, making long documents far easier to read than a fixed-layout PDF.
- Font and size control — Sony Reader firmware can adjust font size in LRF files, a feature often unavailable with image-based PDFs.
- Sideloading personal content — convert notes, reports, or manuscripts to LRF so you can carry and annotate them on your Sony Reader away from a computer.
Supported input formats
The converter accepts a broad range of source formats, including common document types (PDF, DOCX, DOC, ODT, RTF, TXT), popular eBook formats (EPUB, MOBI, AZW3, FB2, LIT, PDB, PML), and several other eBook container formats. This means you can centralise your reading library on a Sony Reader regardless of where the original file came from.
Frequently asked questions
Is this LRF converter free to use?
Yes, the converter is completely free. There is no subscription, no signup, and no hidden charge to convert documents to LRF.
What happens to my uploaded files after conversion?
Your files are processed on the server solely to perform the conversion and are deleted automatically afterwards. They are not stored, shared, or used for any other purpose.
Which Sony Reader models support LRF files?
LRF is natively supported by Sony PRS-series devices such as the PRS-500, PRS-505, PRS-600, and PRS-700. Newer Sony Readers primarily use EPUB, so LRF conversion is most relevant for older hardware.
Can I convert an EPUB or MOBI eBook to LRF?
Yes. Both EPUB and MOBI are accepted input formats, along with many other eBook and document types. Simply upload your file and select LRF as the output.
Will I be notified when my conversion is finished?
If you are logged in to your Conversion-Tool.com account, you can opt in to receive an email notification once the conversion completes — useful for larger files that take longer to process.