MOBI to PDF Converter
Convert Kindle MOBI and KF8 ebook files to PDF documents. Preserves formatting, images, and table of contents. Runs entirely in your browser.
How to Use
Convert Kindle MOBI and KF8 ebook files to PDF in three steps:
- Upload your ebook file — Drag and drop a
.mobior.azw3file onto the dropzone or click to browse. The tool parses the ebook structure entirely in your browser — no data is sent to any server. Book title, author, section count, and cover image are displayed after parsing. - Review the book details — Confirm the detected title and author are correct. The cover image is shown as a thumbnail if the ebook contains one. The section count indicates how many content blocks were found in the file.
- Convert and download — Click the convert button to generate a PDF. The tool renders each ebook section to HTML, then converts the formatted content into a multi-page PDF with proper pagination. The cover image appears as the first page when available.
The tool uses foliate-js for ebook parsing and html2pdf.js for PDF generation, both running entirely in your browser.
About This Tool
Understanding MOBI and KF8 Formats
MOBI (Mobipocket) is an ebook format originally developed by Mobipocket SA and later acquired by Amazon in 2005. It is based on the Palm Database (PDB) container format and uses PalmDOC or HUFF/CDIC compression for text data. A MOBI file contains a PDB header, a PalmDOC header, a MOBI header with metadata, and optionally an EXTH header with extended metadata like author, publisher, ISBN, and cover image references.
KF8 (Kindle Format 8), also known as AZW3, is Amazon's successor to MOBI. It adds support for HTML5, CSS3, embedded fonts, and SVG — features absent in the older MOBI6 format. Many files distributed with a .mobi extension are actually "combo" files containing both a MOBI6 version (for older Kindles) and a KF8 version (for newer devices). This tool detects combo files and uses the KF8 version for better formatting.
How the Conversion Works
The foliate-js library reads the PDB record structure, decompresses text records using PalmDOC or HUFF/CDIC algorithms, and parses the MOBI/KF8 headers to extract metadata. For MOBI6 files, the raw HTML markup is split into sections at each <mbp:pagebreak> tag. For KF8 files, the SKEL and FRAG indices are used to reconstruct the HTML content with proper CSS styling.
Each section is parsed into a DOM Document, and the content nodes are assembled into a formatted layout with serif typography, proper line height, and page break markers. The assembled content is then rendered to a high-resolution canvas via html2canvas and embedded into a PDF document using jsPDF, with automatic pagination at A4 page boundaries.
DRM and Format Limitations
DRM-protected Kindle files (purchased from Amazon with .azw extension) use Amazon's proprietary encryption and cannot be converted by this or any third-party tool without the decryption key. This tool works with DRM-free MOBI and KF8 files — those from Project Gutenberg, Smashwords, personal documents sent to Kindle via email, or any ebook purchased without DRM. The tool checks the encryption flag in the PalmDOC header and clearly notifies you if DRM is detected.
Performance Considerations
MOBI files are typically 1-5MB for text-heavy novels and 10-50MB for illustrated books. The parser decompresses all text records into memory during initialization. For KF8 files using HUFF/CDIC compression, decompression can be slower than PalmDOC due to the Huffman tree reconstruction. The PDF generation step renders each page to a canvas at 2x resolution, which is the most memory-intensive operation. Books with over 500 pages may take 30-60 seconds on mid-range devices. For EPUB ebooks, see EPUB to PDF.
Why Use This Tool
Read Kindle Books Anywhere
MOBI files are primarily designed for Amazon Kindle devices and the Kindle app. Converting to PDF creates a universally readable document that works in any PDF reader on any device — laptops, tablets, phones, and e-readers that support PDF. No Kindle app or Amazon account is needed to read the converted file.
Common Use Cases
- Cross-device reading: Convert MOBI ebooks to PDF for reading on non-Kindle e-readers like Kobo, reMarkable, or Boox devices that don't support MOBI format natively.
- Annotation and markup: PDF readers like Adobe Acrobat, Preview, and Xodo offer robust annotation tools — highlighting, comments, and freehand drawing — that aren't available in all MOBI readers.
- Academic reference: Researchers and students can convert ebook chapters to PDF for inclusion in research collections, citation management tools, and reading lists that standardize on PDF format.
- Printing: PDF preserves exact page layout for printing. Convert MOBI ebooks to PDF when you need a physical copy of a digital book for offline reading or archival.
- Archival: PDF is an ISO-standardized format (ISO 32000) with guaranteed long-term support. Converting from the proprietary MOBI format ensures your ebook collection remains accessible regardless of Amazon's future format decisions.
Complete Privacy
The entire conversion runs locally in your browser. Your ebook files are never uploaded to any server — the parsing, rendering, and PDF generation all happen on your device. Unlike cloud-based converters, there is no file upload, no temporary storage, and no third-party access. Related tools include EPUB to PDF, Text to PDF, Merge PDF, and RTF to PDF.