Sony Portable Reader

An LRF file is an e-book in Sony's BBeB format (BroadBand eBook), the native format of the first Sony Reader devices. If you have one, it most likely comes from an old Sony Reader memory card, a backup of the Sony eBook Library software, or a book archive put together around 2006 to 2010. No current reader or app uses LRF, so the practical answer today is to convert it to EPUB.

Before you go further, check where the file came from. If it sits on an SD card next to MP4 videos from a DJI drone or an Osmo camera, it is not a book at all. See the section on DJI files below.

History: from the Librié to EPUB

Sony introduced BBeB with the Librié EBR-1000EP, launched in Japan in April 2004 as the first commercial reader with an E Ink screen. The format then moved to the Sony Reader PRS-500 (September 2006) and its successors. In July 2008 a firmware update taught the PRS-505 to read EPUB, and in August 2009 Sony announced it would sell only EPUB books by the end of that year. In 2014 Sony closed its Reader Store and moved customers to Kobo. BBeB has been a dead end since then.

How LRF works

BBeB comes in three flavours that are easy to confuse:

• LRS is the editable XML source (the BBeB Xylog format). Hardly anyone ever saw one outside of publishing tools.
• LRF is the compiled, compressed binary the reader actually opens. It is not encrypted.
• LRX is the same thing with DRM, which is what the Sony store sold. An LRX book was tied to the owner's registered devices.

Unlike EPUB, LRF is close to a laid-out book. It can carry pagination data for the reader's font sizes, and the layout was built for the 6-inch, 600 × 800 screens of the time. Text, images and a table of contents survive conversion well. Exact page breaks and the original page numbers do not, because EPUB reflows the text for each screen.

How to open an LRF file today

• Windows, macOS, Linux: the free calibre still reads LRF. Add the file to the library and convert it to EPUB, then read it in any app.
• Phone or tablet: no mainstream reading app opens LRF. Convert to EPUB first; Apple Books, Google Play Books and most Android readers take EPUB directly.
• Kindle: convert to EPUB and send it with Send to Kindle, which accepts EPUB.

Common problems

"LRF file won't open" and it came from a DJI drone

DJI drones and cameras record a small preview copy of each clip with the extension .LRF (low-resolution file). Inside it is ordinary MP4 video. VLC plays it directly, or you can copy it and rename the copy to .mp4. The full-quality footage is in the MP4 file with the same name, so keep that one. An e-book converter cannot do anything with these files.

The book is an LRX file

LRX books are DRM protected and no converter, including ours, will process them. If you bought the book from Sony, see if your purchases were transferred to a Kobo account in 2014, or buy a new EPUB edition.

Strange characters after conversion

Very old LRF files made by third-party tools sometimes have broken metadata or encoding. Converting to EPUB and fixing the title and author in calibre's metadata editor usually takes a minute.

Converting LRF

The most useful targets:

• EPUB for phones, tablets, Kobo, PocketBook and Kindle via Send to Kindle. Once you have EPUB, you can continue with EPUB to PDF if needed.
• PDF for printing or archiving. The text is laid out on US Letter pages with 1-inch margins.
• AZW3 if you copy books to a Kindle over USB.

You can also convert other e-books to LRF. That only makes sense for a Librié or a PRS-500 that never received the EPUB update. Every later Sony Reader reads EPUB, which is the better choice.

LRF at a glance

More detail: LRF on the MobileRead Wiki and the calibre user manual.