LIT is the e-book format of Microsoft Reader, an application Microsoft launched in August 2000 for Windows PCs and Pocket PC handhelds. For a few years it was one of the main formats of the early e-book market, sold by large online bookshops and preinstalled on many Pocket PC and Windows Mobile devices. Microsoft ended the format in 2012. A .lit file you find today most likely comes from an old backup, a CD that came with a book, or an e-book collection from the 2000s.
A short history
Microsoft Reader was one of the first applications to use ClearType, Microsoft's subpixel font rendering, which made text noticeably sharper on the LCD screens of the time. Books could be free or protected by DRM tied to the reader's activation. Publishers could create LIT files with a free add-in for Microsoft Word or with third-party tools. In August 2011 Microsoft announced the end: sales of LIT books stopped on 8 November 2011, and the Reader application was withdrawn from download on 30 August 2012 (see the contemporary report). Already installed copies kept working, but no new version for current Windows was ever released.
What is inside a LIT file
LIT is an extension of CHM, the compiled HTML Help format known from Windows help files. Inside the container are:
- the text in OEBPS 1.0 markup, essentially HTML 4 written as well-formed XML, the same Open eBook standard that later evolved into EPUB,
- a simplified CSS stylesheet,
- images in GIF, JPEG or PNG,
- metadata and a table of contents.
The content is compressed with LZX, the same algorithm used in Microsoft's CAB archives, and markup is stored in a compact binary form. Microsoft never published a full specification; details come from reverse engineering, summarised in the MobileRead wiki.
How to open LIT today
No current Microsoft software reads LIT, and there is no official Microsoft Reader for Windows 10 or 11. The practical option is calibre on Windows, macOS or Linux: its viewer opens DRM-free LIT files, and its converter turns them into a format every reader understands. Old installers of Microsoft Reader on download sites are unsupported and not worth the risk.
Common LIT problems
LIT file won't open on Windows 11
Windows has no LIT reader any more. Convert the book to EPUB or PDF, or open it in calibre.
LIT won't convert
Books bought in the 2000s were often protected and tied to the activated Microsoft Reader of the original buyer. Such protected files cannot be converted. DRM-free LIT files, including most free classics and self-published books, convert without problems.
Converting LIT
Because LIT carries clean, well-structured HTML, it converts unusually well; the FAQ of the calibre e-book manager even puts LIT at the top of its list of preferred source formats. The obvious target is LIT to EPUB: chapters, table of contents, images and basic styling carry over, and the result works on almost any reader. For a Kindle, choose AZW3; for printing, PDF. Converting to LIT still works, and the file is written without DRM, but it is useful only for old Pocket PC or Windows Mobile devices that still have Microsoft Reader installed.
LIT at a glance
| Developer | Microsoft |
|---|---|
| First release | August 2000, with Microsoft Reader |
| End of support | sales stopped November 2011, Reader withdrawn 30 August 2012 |
| Type | CHM-based container with OEBPS 1.0 (HTML/XML), CSS and images |
| Compression | LZX, lossless |
| Specification | proprietary, never published |
| Typical use today | archived e-books from the 2000s, converted to EPUB |
Calibre's view on source formats is in its FAQ.