⚙️ PDF Output Settings
📚 Upload MOBI File
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Convert MOBI ebook files to professional PDF documents instantly. Reads the MOBI binary format directly in your browser — your files never leave your device.
Upload your MOBI file below, preview the extracted content, customize settings, and download your PDF instantly.
Drag & Drop MOBI file here
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Upload a MOBI file above and click "Parse MOBI & Preview" to begin
The design principles behind this tool — and what to look for in any ebook converter you use.
Your MOBI is parsed and re-rendered entirely in your browser — never on a remote server.
The title and author are pulled from the MOBI's own EXTH headers, not guessed from filenames.
Font size, line spacing, margins, document title and author — every option is exposed, not paywalled.
No email signup, no daily quotas, no watermarks, no "upgrade to remove limits" — ever.
Converts MOBI ebooks to readable PDF documents entirely in your browser — fast, private, and packed with useful features.
prefers-color-scheme, with no manual toggling.From upload to PDF download in under a minute. No account, no software needed.
For the curious: a look at exactly what the tool does between the moment you drop your MOBI and the moment your PDF downloads.
When you drop or select a .mobi file, the browser hands it to JavaScript as a Blob. The bytes never touch the network — they live only in your tab's memory.
The first 78 bytes contain the Palm Database header. We pull out the book name, record count, and the offset table that tells us where every internal record lives.
Record 0 contains the PalmDOC header: compression type, total text length, number of text records, encryption flag and encoding. If DRM is detected (encType ≠ 0) we stop here with a clear error.
If the MOBI header carries an EXTH block, we walk through each record by type — code 100 for author, 503/524 for the full book title — to autofill the form fields.
For each text record we strip MOBI's trailing bytes, then run PalmDOC LZ77-style decompression to recover the original HTML stream. Huffman-compressed MOBIs are rejected here with a helpful message.
Block tags become line breaks, page-breaks become section dividers, HTML entities are decoded, runs of whitespace collapsed. The output is clean paragraphs ready to typeset.
The first 2,000 characters appear in the preview pane. Word count, paragraph count and estimated PDF pages are computed and shown in the stats bar.
jsPDF creates an A4 portrait document, draws a styled cover page with your title and author, then lays out every paragraph with your chosen font, spacing and margins.
The finished PDF is offered as a Blob download. Nothing uploaded; it moves straight from your tab's memory to your disk.
Understanding the structure of a MOBI file explains why some convert cleanly and others can't be handled in a browser.
The MOBI format sits inside a Palm Database (PDB) container — the same kind of file format originally used by Palm Pilot organizers in the late 1990s. Each file is a sequence of records, with a header describing how many records there are and where each one starts. The MOBI specification was developed by Mobipocket, a French software company acquired by Amazon in 2005, which is why MOBI later became the foundation for Kindle's ebook format.
Inside a MOBI, the actual ebook text lives in compressed records. There are three possible compression modes: None (rare in practice), PalmDOC (a fast LZ77-style scheme, by far the most common), and Huffman/CDIC (used by some commercial Kindle store books for higher compression). This tool supports None and PalmDOC; Huffman-compressed files are rejected with a clear message because reimplementing Amazon's Huffman tables in JavaScript is impractical for a single-purpose converter.
Most modern MOBI files carry an EXTH ("Extended") metadata block after the MOBI header. EXTH stores key/value records by numeric type code: 100 for author, 101 for publisher, 503 for the long-form book title, 524 for language, 106 for publication date, and many more. This tool walks the EXTH table and pulls out the title and author automatically so you don't have to type them.
If you bought an ebook from the Amazon Kindle store, it's almost certainly encrypted with Amazon's DRM. The encryption flag (encType) in the PalmDOC header will be non-zero, and the text records will be unreadable garbage without the per-device decryption key. This tool refuses to attempt conversion on DRM-locked files — that's not a limitation, it's the correct, lawful behaviour. For files you own outright (e.g. ones you wrote yourself, public-domain Project Gutenberg ebooks, or DRM-free purchases from authors and indie publishers), conversion just works.
Inside the compressed text records, MOBI stores its content as simplified HTML — paragraphs as <p>, page breaks as <mbp:pagebreak>, line breaks as <br>, and so on. This converter flattens the HTML into paragraphs, decodes character entities, and feeds the clean text into jsPDF for layout.
From the Palm Pilot era to Kindle and beyond — how the MOBI format shaped (and then yielded to) modern ebooks.
MOBI is great for Kindle, but PDF is what you reach for when MOBI can't go where you need it. Here's where conversion pays off.
PDF prints predictably across printers; MOBI doesn't. Convert before sending an ebook to your home or office printer.
PDFs open natively on Windows, macOS, Linux, ChromeOS, iOS and Android. MOBI needs a dedicated reader app.
Project Gutenberg and similar archives offer DRM-free MOBIs. Convert them to PDF for archiving alongside other public-domain works.
Generate a quick PDF proof of your own MOBI before sending to beta readers, reviewers, or print-on-demand services.
PDFs support stable highlight and comment tools across nearly every reader. MOBI's annotations live inside Kindle's ecosystem.
Some recipients can't open MOBI at all. A PDF is the lowest-common-denominator format — everyone can open it.
PDF/A is the ISO standard for long-term archival. MOBI is a vendor format whose future depends on Amazon's product roadmap.
Prepare a PDF excerpt of a public-domain or self-owned book to print and hand out at a reading club meeting.
Distribute lecture notes and DRM-free reading material as PDF so every student can open it on any device, no Kindle needed.
Convert old MOBI archives into searchable PDFs that integrate with reference managers like Zotero and Mendeley.
PDFs work in any offline reader on phones and tablets — perfect for flights where the Kindle app might balk.
PDFs allow easy text selection in any reader, making it simple to copy quotes for citation, translation, or note-taking.
If MOBI support is ever removed from your favourite app or device, you'll still have a clean PDF you can read forever.
Receive a publisher's review-copy MOBI, convert to PDF, mark it up in Acrobat, and send back annotated feedback.
Convert a MOBI you legally own to PDF, print it through a service like Lulu or print-bind locally, and gift the bound book.
Some school portals only accept PDF. Convert your draft MOBI manuscript to PDF for assignment uploads.
The four major formats you'll see in the ebook world, side by side, so you know which one to use when.
| Property | 📚 MOBI | 📖 EPUB | 🟧 AZW / AZW3 | |
|---|---|---|---|---|
| Standardization | Vendor (Mobipocket / Amazon) | Open IDPF / W3C standard | Vendor (Amazon) | ISO 32000 |
| Reflowable text | Yes | Yes | Yes | Fixed layout |
| Universal reader support | Limited | Wide | Kindle only | Every device |
| Opens in any browser | No | Some | No | Yes |
| Native print fidelity | Varies | Varies | Varies | Excellent |
| DRM common in practice | Sometimes | Sometimes | Yes (almost always) | Rare |
| Underlying content | Simplified HTML | HTML5 + CSS3 | HTML5 + CSS3 | PDF page objects |
| File extension | .mobi / .prc | .epub | .azw / .azw3 / .kfx | |
| Long-term archive friendly | Vendor risk | Open standard | Vendor lock-in | PDF/A standard |
| Best for | Older Kindle compatibility | Modern open ebooks | Kindle store reading | Sharing & printing |
Small habits and settings choices that make a noticeable difference in how clean your converted PDF turns out.
If you bought the book from the Kindle store, it's encrypted. Use a DRM-free source — a book you wrote, a Project Gutenberg download, or a direct author file.
That's a comfortable reading default for novels and non-fiction. Bump to 12pt if your eyes prefer larger text.
If you plan to print and bind the PDF, set margins to Wide (25mm) so there's room for the binding edge without text loss.
For on-screen reading on small tablets, Narrow (15mm) keeps text large and the reading column comfortable.
If the auto-detected title looks like a filename or has underscores, just type the real title in the field before generating.
Very old MOBIs (pre-2003) may have no EXTH author. Type it in to keep your library cover pages consistent.
Always click "Parse MOBI & Preview" first to confirm extraction worked. A few seconds of preview saves you from generating a broken PDF.
If the preview shows odd characters, the encoding chip will say WINDOWS-1252 — that's normal. The PDF text should still render correctly.
If you see a Huffman error, your MOBI uses a compression scheme this tool doesn't support. Re-export from Calibre with standard compression.
For DRM-protected or KF8/AZW3-only files, the desktop Calibre app is the standard tool — it handles cases this browser tool intentionally doesn't.
Conversion is one-way: the PDF doesn't preserve all reflowable-ebook features. Hang on to the source MOBI in case you want to remake the PDF with different settings.
The downloaded filename is derived from your Document Title. A clean, descriptive title gives you a clean filename automatically.
MOBI-to-PDF isn't just a Kindle workflow — many roles bump into it regularly.
Generate quick PDF proofs of MOBI deliverables before sending to editors, beta readers, or print-on-demand vendors.
Receive review-copy MOBIs from publishers, convert to PDF for highlighting and annotation in Acrobat.
Distribute public-domain reading materials as PDF rather than MOBI so every student can open them, no Kindle needed.
Convert DRM-free MOBI archives to PDF for long-term institutional storage in formats less likely to be retired.
Maintain personal research libraries by converting collected MOBIs into searchable PDFs that drop neatly into Zotero or Mendeley.
Convert manual ebook material into PDF for inclusion in evidence bundles and discovery packages where MOBI isn't accepted.
Turn early MOBI drafts of technical manuals into PDF reviewers can mark up, then return for revision rounds.
Generate a PDF preview of your KDP-bound MOBI to confirm word count, length, and cover-page layout before final submission.
Convert public-domain literature MOBIs from Project Gutenberg into PDFs for class reading and easy annotation.
Hand out a printable PDF excerpt of the month's pick to participants who don't own a Kindle.
Convert MOBI source files into PDF for easier visual comparison alongside the in-progress translation document.
Maintain a personal "future-proof" library by snapshotting every MOBI you own as a PDF copy you control.
Transparency matters. Here's exactly what happens when you use this converter.
This tool uses a client-side JavaScript library — jsPDF — that runs entirely inside your browser tab. Your MOBI file is read from your device with the FileReader API, parsed in memory, decompressed with our embedded PalmDOC implementation, and rebuilt into a PDF offered to you as a Blob download.
The tool itself never needs to upload your file to a server. Conversion speed depends entirely on your device's CPU and available memory, not on a remote service.
Although the conversion logic is local, modern websites do receive normal browser metadata such as your IP address, user agent, and referrer. If you're working with sensitive material — early manuscripts, confidential drafts, unpublished work — it's always smart to verify how a tool behaves. You can open your browser's developer tools and inspect the Network tab while converting to confirm no MOBI data is being sent externally.
For background reading on browser security and safe handling of personal files, see the Electronic Frontier Foundation's privacy resources.
By design, this tool will not attempt to bypass DRM. If the MOBI's encryption flag is non-zero — typical for Kindle store purchases — we stop with a clear error rather than trying to decrypt the content. That's not a limitation; it's the correct behaviour both technically and legally. If you want to convert ebooks you've bought, use the appropriate official channel.
When you close the browser tab, the MOBI bytes and the generated PDF are discarded automatically. There's no account, no cloud storage, no history. Save the downloaded PDF to your device before closing the tab if you want to keep it.
Don't take our word for it. Press F12 (or Cmd+Option+I on Mac) to open developer tools, switch to the Network tab, then drop a MOBI and run conversion. You'll see the page's own assets loading, but no outbound request carrying your ebook bytes. That's the difference between a server-side and a client-side tool.
Rough expectations for common ebook sizes. Numbers vary based on font size, line spacing, margins, and how dense the source text is.
| Source MOBI | Typical Words | MOBI Size | PDF Size (Normal) | Est. PDF Pages | Conversion Time* |
|---|---|---|---|---|---|
| Short story | 10,000 | ~60 KB | ~100 KB | ~33 | < 1 second |
| Novella | 30,000 | ~150 KB | ~250 KB | ~100 | 1 – 2 seconds |
| Standard novel | 80,000 | ~400 KB | ~650 KB | ~270 | 2 – 4 seconds |
| Long novel | 150,000 | ~700 KB | ~1.2 MB | ~500 | 3 – 6 seconds |
| Non-fiction reference | 200,000 | ~1.1 MB | ~1.7 MB | ~670 | 5 – 9 seconds |
| Epic fantasy | 400,000 | ~2.2 MB | ~3.5 MB | ~1,300 | 10 – 18 seconds |
| Compiled trilogy | 800,000 | ~4.5 MB | ~7 MB | ~2,700 | 25 – 45 seconds |
*Times measured on a typical 2024-class laptop. Mobile devices and older hardware may take longer.
A lot of folklore swirls around ebook conversion. Here are the most common myths and the actual truth.
Calibre is excellent for complex cases, but modern browsers can parse standard MOBI files entirely in JavaScript. No install required for DRM-free files.
Some do — but client-side tools like this one run entirely in your browser. You can verify it in DevTools Network tab in 10 seconds.
For pure text content, PDF and MOBI are similar in size. PDFs only balloon when they contain heavy images, which we don't carry across.
This tool intentionally won't try. DRM removal is a legal grey area and outside this tool's scope. Use the appropriate official channel.
PRC and MOBI share the same Palm Database container. This tool treats them identically — drop either and it just works.
This text-focused converter extracts words and structure, not images. For image-rich MOBIs (manga, illustrated books), a desktop tool like Calibre is a better fit.
MOBI supports None, PalmDOC, and Huffman compression. This tool handles None and PalmDOC (the most common); Huffman files require Calibre.
PDF is a fixed-layout format by design. If you need reflowable text after conversion, keep the source MOBI or use EPUB as an intermediate.
If your output doesn't look the way you expected, one of these is usually the cause.
Your MOBI was bought from a store that wraps content in DRM (usually Amazon). The encryption flag in the header is non-zero and the text records are unreadable without the per-device key. Fix: use a DRM-free source — Project Gutenberg, Standard Ebooks, your own writing, or the publisher's directly-delivered MOBI for review.
This MOBI uses Huffman compression, often seen in older commercial Kindle books. Implementing the Huffman tables in browser JavaScript is impractical. Fix: open the file in Calibre, convert it to a standard PalmDOC-compressed MOBI (or directly to EPUB/PDF), and re-upload if needed.
Old MOBIs sometimes use Windows-1252 instead of UTF-8 for encoding. The tool detects this and switches automatically, but if odd characters still show up the original file may be corrupt or mis-tagged. Fix: open the file in Calibre, which can often clean and re-save with a proper encoding before you re-upload.
The MOBI has no EXTH title record, so the tool falls back to the PalmDB book name — which is often the original filename with underscores. Fix: simply type the real title in the Document Title field before generating. It overrides the auto-detection.
Two common causes: the file is image-only (a manga or photo book), or the records use a compression scheme we don't support. Fix: use Calibre, which supports a wider range of MOBI variants and can extract text and images together into PDF.
Very large MOBIs (multi-book omnibuses, 500,000+ words) can push past browser memory limits, especially on phones. Fix: split the MOBI into individual books with Calibre first, then convert each one separately.
Long ebooks take longer to lay out paragraph-by-paragraph. A 400,000-word epic fantasy can take 15+ seconds on an older device. Fix: close other tabs, free up memory, or try with a smaller chapter first to confirm the file works.
This converter is text-focused. Embedded images, cover artwork and illustrations are intentionally not carried into the PDF. Fix: use Calibre for image-rich conversions; it preserves more visual elements at the cost of being a desktop install.
Need to convert other file types to PDF or work with existing PDFs?
Curated links to authoritative documentation if you want to go deeper into ebook formats, PDF standards, and web technology.
Short, friendly definitions for the technical terms you'll see when working with ebooks and PDFs.
Everything you need to know about converting MOBI files to PDF.