Question 1

What does this tool do?

Accepted Answer

Converts Microsoft Reader LIT ebooks to PDF in your browser. LIT is a Microsoft ebook format (discontinued in 2012, but old books still circulate). We parse the LIT header (8-byte signature 'ITOLITLS' + version + section count + section table), extract text from each text section (we skip LZX-compressed sections — see honesty clause below), split into chapters by heading patterns, and render to PDF using pdf-lib.

Question 2

What is the LIT format?

Accepted Answer

LIT (Microsoft Reader) is an ebook format Microsoft released in 2000 and discontinued in 2012. The format is based on the Open Ebook Publication Structure (OEBPS) — sections containing HTML or plain text, optionally compressed with LZX (a Huffman+LZ77 variant). The LIT container starts with an 8-byte signature 'ITOLITLS', then a 4-byte version, a 4-byte header size, a 4-byte section count, and a section table (each entry: 4-byte offset + 4-byte size + 4-byte flags).

Question 3

Can it extract text from all LIT files?

Accepted Answer

Honest answer: not from LZX-compressed sections. LZX is a complex compression format (used in Windows Imaging Format WIM files, and some CHM help files). A pure-JS LZX decoder is ~50KB+ and we don't bundle it. Most LIT files have an uncompressed section 0 (metadata XML) and may have uncompressed text sections (older LITs); we extract those. For LZX-only LITs, conversion fails with a clear error message. Use Calibre (desktop) to convert LZX-compressed LITs to PDF — it has a complete LZX implementation.

Question 4

How does chapter detection work?

Accepted Answer

After extracting text from the LIT sections, we look for heading patterns: Markdown-style '# Chapter 1', 'Chapter 1', 'Part 1', or ALL-CAPS lines (5+ chars, no lowercase). Each heading starts a new chapter. If no headings are found, the entire text becomes one chapter. The output PDF has one page per chapter (with wrapping) plus chapter headings.

Question 5

What extra features does this tool have compared to others?

Accepted Answer

10 extras: (1) Drag-drop file input. (2) LIT signature detection ('ITOLITLS'). (3) Section table parsing (offset, size, flags). (4) Compression detection (flag bit 0 = LZX compressed). (5) Stats — section count, text section count, compressed section count, chapter count, word count. (6) Custom title (defaults to LIT metadata title). (7) Adjustable font size (8-24pt). (8) Page size choice (US Letter or A4). (9) History (localStorage — last 10 conversions). (10) Shareable URL with options.

Question 6

Is my LIT file uploaded anywhere?

Accepted Answer

No. All LIT parsing and PDF generation runs in your browser using pure JavaScript + pdf-lib. File contents never leave your device. Only file summaries (filename, section count, word count) are saved to local history.

Question 7

Can I convert DRM-protected LIT files?

Accepted Answer

LIT files could be DRM-protected via Microsoft's 'Owner Exclusive' flag. Microsoft disabled the DRM activation servers in 2012, so old DRM-protected LITs can no longer be activated on new devices. If your LIT is DRM-protected, conversion will fail because we can't decrypt it. Most free LIT downloads (Project Gutenberg, Baen Free Library) are DRM-free.

LIT to PDF Converter

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