MOBI to PDF Converter
Upload a Kindle MOBI e-book and convert it to a layout-stable PDF instantly
Drop a MOBI file here, or click to select
Supports .mobi format (DRM-free), max 5MB
What is MOBI to PDF?
MOBI to PDF is an online e-book conversion tool that turns .mobi files into PDF (Portable Document Format). MOBI is the e-book format created by Mobipocket SA (acquired by Amazon in 2005) and long used as one of the primary formats on Kindle devices. Its body text is stored as compressed HTML fragments inside a Palm Database (PDB) binary container, and the text reflows to fit the screen. PDF, by contrast, is a fixed-layout format where every page has a defined size and coordinate system, so it looks identical on any device.
Converting MOBI to PDF means freezing flowing text into paginated pages. The conversion engine first parses the PDB container, reads the PalmDOC and MOBI headers, decompresses the text records into a complete HTML document, extracts the cover and image records, then repaginates everything according to a chosen page size, margins, and font size before rendering it to PDF. The result is ready for printing, archiving, annotating on a computer, or sharing with someone who has no Kindle. The whole process runs server-side, and the original MOBI is deleted from the server as soon as conversion finishes - no copy retained.
Typical use cases: printing a few pages of an older Kindle MOBI, delivering a self-made or public-domain MOBI as a fixed-layout PDF, generating a stable page-numbered copy of an academic text for citation, or simply reading on a computer with a PDF viewer instead of Kindle software. Three steps, no Calibre install required. Note that since late 2022 Amazon has stopped accepting MOBI via Send to Kindle in favor of EPUB, so MOBI is being phased out - but existing MOBI files can still be converted with this tool.
How to Use
How to use
- Click the upload area or drag and drop a MOBI file - only .mobi is supported
- Click "Convert to PDF" and the server will parse, decompress, and paginate the book in seconds
- Once done, click "Download PDF" to save the file to your device
- Need to convert more files? Click "Convert Another File" to start fresh
Conversion Checks
- Conversion quality depends on whether the MOBI's encoding, CSS styles, and image resources are complete; older MOBI cannot embed fonts, so the PDF is repaginated with standard server-side fonts.
- Open the generated PDF and check pagination, the table of contents, and images before sharing - especially for books with many illustrations or tables.
Use Cases
Technical Principle
A MOBI file is fundamentally a Palm Database (PDB) binary container that follows the PalmOS database format. It opens with a 78-byte PDB header: a database name (32 bytes), attributes, version, creation/modification times, a type identifier (usually BOOKMOBI), a creator identifier (typically MOBI or TEXt), the total record count, and a record offset table - one entry per record giving its byte offset and attributes within the file. Everything in a MOBI (text, images, indices) is split into equal-sized chunks (usually 4096 bytes each) stored sequentially as PDB records: record 0 is the header, followed by text records, then image records.
Record 0 is the key to parsing a MOBI and contains three headers back to back. First is the PalmDOC header: it gives the compression scheme (1 = none, 2 = PalmDOC/Huffdic dictionary compression), total text length, text record count, per-record size, and the encryption type. Next is the MOBI header, which begins with the identifier "MOBI" and carries the header length, MOBI type, text encoding (CP1252 or UTF-8), unique ID, generator version, the first image record index (firstImageIndex), Huffman-table fields, and the EXTH flag. If the EXTH flag is set, the EXTH header follows immediately: it begins with "EXTH" and lists type-length-value records holding metadata such as author, title, publisher, ISBN, ASIN, and publishing date.
The body text is spread across records 1 through N and must be decompressed record by record according to the PalmDOC header before being concatenated into a complete HTML document. PalmDOC compression is a byte-oriented LZ77 variant: a flag bit distinguishes literal bytes from backreferences, where a backreference is a (distance, length) pair that copies a span from the already-decompressed output buffer to compress repeated content; Huffdic is MOBI's custom Huffman scheme. The resulting HTML is a restricted subset (close to HTML 3.2/4) with limited CSS - older MOBI does not support SVG, nested tables, or embedded fonts (KF8/AZW3 loosened these limits). Images are referenced via <img recindex="00001">, where recindex points to the nth image record starting from firstImageIndex.
MOBI-to-PDF conversion therefore breaks down into four steps: parse the PDB container to obtain record offsets -> read the PalmDOC/MOBI/EXTH headers of record 0 to determine encoding, compression, and metadata -> decompress the text records into HTML and extract the image records -> lay out and paginate the HTML at a chosen page size and margin, then render it to PDF (fonts embedded as TrueType subsets, images re-encoded as JPEG/Flate, following ISO 32000-1/2). This pagination step is identical to EPUB-to-PDF, so converters often use a headless browser (headless Chromium) print-to-PDF pass for the highest CSS fidelity; Calibre's ebook-convert ships a MOBI input plugin and its own rendering pipeline and is the de facto standard on the command line, while KindleUnpack can first split a MOBI into HTML plus images for a downstream renderer. This tool only accepts DRM-free MOBI; titles locked with Amazon's DRM cannot be parsed. .azw3/KF8 is the modern successor to MOBI, structurally closer to EPUB, and requires its own tooling.
- PDB container structure: a 78-byte Palm database header (database name, type BOOKMOBI, creator, record count + offset table), with content split into roughly 4096-byte records stored sequentially
- Record 0 holds three headers: PalmDOC header (compression, text length, record size) -> MOBI header (encoding, firstImageIndex, EXTH flag) -> EXTH header (author, title, ISBN, ASIN and other metadata)
- Text decompression: records 1 through N are decompressed per the PalmDOC header (none / PalmDOC LZ77 dictionary / Huffdic Huffman) and concatenated into the full HTML
- HTML subset and images: MOBI uses a restricted HTML (close to HTML 3.2/4) with limited CSS and no SVG or embedded fonts in older versions; images are stored as separate records referenced by <img recindex="00001">
- Four conversion steps: parse the PDB -> read headers for encoding/compression/metadata -> decompress text and extract images -> paginate and render to PDF (font subsets embedded, images re-encoded, ISO 32000-1/2)
- Engines and limits: often headless Chromium print-to-PDF for CSS fidelity, or Calibre ebook-convert (ships a MOBI input plugin); only DRM-free MOBI is accepted, and .azw3/KF8 is its modern successor
- Format status: Amazon stopped accepting MOBI via Send to Kindle in late 2022 in favor of EPUB; existing MOBI files can still be converted, but the format is being phased out
Examples
Print an Old Kindle Book
Convert a MOBI novel you sideloaded onto your Kindle years ago to PDF and print just the pages you need for your notesArchive Academic Material
Turn a MOBI textbook into a fixed-page PDF so 'page 47' is unambiguous when citingRead on a Computer
No Kindle client? Convert MOBI to PDF and flip through it in a browser or PDF viewerFAQ
Does my MOBI file stay on my device?
No. The .mobi file is uploaded to our conversion server, parsed and rendered into a PDF, and returned as a download. Treat anything you upload as if it leaves your device, and avoid sending unredacted sensitive material. The original file is deleted from the server automatically after conversion.
Which e-book formats are supported?
This tool only accepts .mobi. .epub, .azw3, .pdf, and other formats need their own conversion tools; EPUB can be handled by our EPUB to PDF tool, and .azw3/KF8 is the modern successor to MOBI with a different structure that needs separate handling.
Can I convert DRM-protected MOBI files?
No. Kindle titles locked with Amazon's DRM cannot be opened by the converter. Use a DRM-free MOBI obtained through legitimate means, such as a self-made book, a public-domain title, or a file you have explicit permission to use.
Will my fonts and layout be preserved?
Older MOBI cannot embed fonts, so the PDF is typeset with standard server-side fonts (including CJK fonts), and line breaks and pagination may differ slightly from what you see on a Kindle. Only KF8/AZW3 supports embedded fonts, and that is a different format. Chapter structure, the cover, and illustrations are preserved as much as possible.
Does the converted PDF have fixed page numbers?
Yes. MOBI is reflowable and has no fixed page numbers; PDF is fixed-layout, so every page has a defined number and coordinate. The page size, margins, and font size are set by the conversion engine, so the PDF's page numbers do not correspond to positions in your Kindle.
Are images, the cover, and the table of contents kept?
The cover is usually rendered as the first PDF page, and inline images (JPEG/GIF/BMP) are re-encoded and embedded. If the MOBI's table of contents can be parsed from its embedded index or HTML anchors, it is preserved as PDF bookmarks; chapter headings fall onto their corresponding pages according to the pagination rules.
Why is my PDF much larger than the original MOBI?
MOBI text is compressed with PalmDOC/Huffdic and the HTML subset is very compact, so the file is small; PDF stores rendered fixed pages and also embeds font subsets and re-encoded images. Books with many illustrations often grow several times in size after conversion - this is a normal consequence of the format.