HTMLZ vs LRF
A detailed comparison of HTMLZ eBook and Sony LRF eBook — file size, quality, compatibility, and which format to choose for your workflow.
HTMLZ eBook
eBooksHTMLZ is a zipped HTML ebook format used by Calibre as a lossless intermediate representation. It packages HTML content, CSS stylesheets, and images into a single ZIP archive, preserving full formatting fidelity during ebook conversion chains.
About HTMLZ filesSony LRF eBook
eBooksLRF (BBeB Book) is a proprietary ebook format developed by Sony for their Reader line of e-ink devices. It supports reflowable text, images, and basic formatting, but has been superseded by EPUB on newer Sony Reader models.
About LRF filesStrengths Comparison
HTMLZ Strengths
- Simpler than EPUB.
- ZIP-of-HTML portability.
- Calibre-native.
LRF Strengths
- Sony PRS-native.
- Rich layout.
- Calibre-readable.
Limitations
HTMLZ Limitations
- Niche — no reader support.
- Not a mainstream delivery format.
- Calibre-only.
LRF Limitations
- Deprecated.
- Sony exited the market.
- No new content.
Technical Specifications
| Specification | HTMLZ | LRF |
|---|---|---|
| MIME type | application/x-htmlz | application/x-sony-bbeb |
| Extension | .htmlz | .lrf |
| Container | ZIP + HTML | — |
| Tool | Calibre | — |
| Native reader | — | Sony PRS series (retired 2014) |
Typical File Sizes
HTMLZ
- Typical novel 300 KB - 2 MB
LRF
- Typical novel 500 KB - 3 MB
Ready to convert?
Convert between HTMLZ and LRF online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.
Frequently Asked Questions
HTMLZ (HTMLZ eBook) is an ebook format designed for reading long-form text on dedicated e-readers, tablets, and ebook apps. It is part of the ebooks family and typically supports reflowable text, embedded images, chapter navigation, cover art, and metadata (title, author, ISBN) in a portable package.
LRF (Sony LRF eBook) is an ebook format designed for reading long-form text on dedicated e-readers, tablets, and ebook apps. It is part of the ebooks family and typically supports reflowable text, embedded images, chapter navigation, cover art, and metadata (title, author, ISBN) in a portable package.
Dedicated e-readers — Kindle, Kobo, Nook, Pocketbook — support the most common ebook formats. On phones, Apple Books, Google Play Books, Moon+ Reader and KOReader all handle HTMLZ. For desktop reading, Calibre is the universal ebook viewer and library manager. Convert to EPUB or PDF for maximum compatibility.
Dedicated e-readers — Kindle, Kobo, Nook, Pocketbook — support the most common ebook formats. On phones, Apple Books, Google Play Books, Moon+ Reader and KOReader all handle LRF. For desktop reading, Calibre is the universal ebook viewer and library manager. Convert to EPUB or PDF for maximum compatibility.
Upload your HTMLZ to KaijuConverter and pick EPUB, MOBI, PDF, AZW3, or similar targets. Our Calibre-powered pipeline preserves chapter structure, embedded images, cover art, and metadata. Conversion takes seconds for typical novels; long technical books with many images may take a little longer.
EPUB is the open ebook standard — it plays on every e-reader except older Kindles and in every major ebook app. PDF is better for fixed-layout content (textbooks, coffee-table books) and printing. Pick EPUB when the ebook is reflowable text, PDF when the layout matters more than the reading experience.