A private, client-side web tool to turn digital comic archives (.cbz, .cbr, .zip, .rar) into properly bound, print-ready PDFs for personal physical reading.
Important
This project strictly does NOT endorse, encourage, or facilitate piracy.
This software is a personal formatting utility designed exclusively for printing and binding comics that you legally own, created, or hold the rights to print for personal physical use:
- Original comics, manga, or graphic novels you created, drew, or wrote;
- Works you commissioned, contracted, or hold publishing rights to;
- Material in the public domain or released under licenses permitting personal reproduction;
- Legally purchased digital copies where your jurisdiction or license grants you the right to format-shift or create a personal physical archival copy for private use.
Zero Content Hosted, Stored, or Transmitted: This repository contains no comics, no scans, and no artwork. The application downloads nothing, tracks nothing, and transmits no files. All extraction, layout computation, and PDF generation happen 100% client-side inside your web browser.
Converting a folder of images into a basic PDF is trivial. Making a PDF that binds cleanly into a physical booklet is where things go wrong:
- Split spreads across page turns: Double-page spreads split in half can accidentally land on opposite sides of a physical page turn, breaking the artwork across sheets instead of opening as a seamless spread.
- Page count arithmetic: A folded booklet (saddle-stitched) requires a total page count that is a multiple of four. If your story runs 25 pages, a physical fold requires padding with blanks—which often displaces your intended back cover.
- Scanner cards & credit pages: Stray landscape credit cards get accidentally sliced in half if treated as comic spreads.
- Blank padding pages: Blank pages inside a comic break the reading rhythm. Authentic vintage comic books filled these gaps with house adverts and period announcements.
This tool resolves these issues interactively directly in your browser.
- 100% Client-Side & Private: Powered by WebAssembly (
node-unrar-js) and pure JavaScript libraries (fflate). Your comic files never leave your machine and no backend server is required. - Archive Support: Drag and drop
.cbz,.cbr,.zip, and.rarfiles directly into the web interface. - Interactive Visual Preview: Real-time dual-page booklet preview and full page grid showing exact trim boxes, spreads, padding slots, and cover placements.
- Smart Spread Splitting: Automatically detects landscape double-page spreads, splits them into left/right halves, and supports both Left-to-Right (LTR) and Right-to-Left (RTL manga) reading orders.
- Duplex Parity Alignment: Aligns spreads so the left and right halves always face each other across the fold once printed and bound.
- Booklet Padding: Automatically pads your document to multiples of 4 (or custom booklet multiples) to guarantee clean folding.
- Balanced Advert & Filler Pool: Drop in period advertisements or custom filler images to occupy padding pages. The distribution algorithm guarantees that the difference between the maximum and minimum frequency of any advert across the comic is at most 1, with deterministic book seeding and no consecutive duplicate placements.
- Flexible Back Covers: Choose between auto-generated art compositions, solid color backings, variant covers, dedicated pages from the archive, custom file uploads, or advert pool selections.
- Live Pre-Print Audit: Instantly validates multiple-of-4 booklet geometry, checks facing spread pairs, and monitors advert distribution balance before you generate your final PDF.
- Lossless Embedding: JPEG streams are embedded directly into the generated PDF without lossy re-compression.
- Node.js (version 18 or newer)
npm(installed with Node.js)
# Navigate to the web app directory
cd web-app
# Install dependencies
npm install
# Launch local development server with HMR
npm run devOpen http://localhost:5173 in your web browser.
- Drop your comic archive: Drag and drop any
.cbzor.cbrfile onto the dropzone. - Review the Live Audit: Check the top audit banner to confirm that your page count is a multiple of four and that all split spreads face each other properly.
- Adjust Settings:
- Presets: Quick options for Print & bind (saddle-stitch booklet), Faithful copy (preserve source exactly), or Two-up on screen (facing reader).
- Double-page spreads: Toggle splitting, alignment, and reading direction (LTR / RTL).
- Advert Pool: Optionally drop filler images to replace blank pages. Frequency badges indicate how many times each advert appears in the planned volume.
- Back Cover: Select an auto-composed cover, custom upload, or advert.
- Binding & Margins: Configure inner gutter binding margins, bleed allowances, and target paper sizes.
- Build PDF: Click Build PDF. The PDF is assembled client-side and automatically offered as a download.
You can build the production-ready static assets:
cd web-app
npm run buildThe compiled bundle is output to web-app/dist/. Because the application is entirely static and requires no server runtime, you can deploy this directory to any static web host:
- Cloudflare Pages
- Vercel
- Netlify
- GitHub Pages
- Amazon S3 / Any Static Web Server
Inside web-app/:
| Command | Description |
|---|---|
npm run dev |
Starts the Vite local development server with hot module replacement |
npm run build |
Compiles TypeScript and builds the optimized production bundle |
npm run lint |
Runs the high-performance Oxlint linter across the codebase |
npm run preview |
Previews the production build locally |
This software is released under the MIT License.
This license covers the application source code only. It does not grant rights to any third-party comics, artwork, or publications formatted with this tool. Users are solely responsible for ensuring they hold the appropriate rights or permissions for any material they process.