The latest articles on DEV Community by Neng (@nengdev). https://dev.to/nengdev https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4030616%2F1e82d667-478a-4b10-970c-c035e377a12a.png https://dev.to/nengdev en Neng Wed, 15 Jul 2026 15:05:40 +0000 https://dev.to/nengdev/i-built-a-browser-based-cbz-to-pdf-converter-that-keeps-comics-private-330n https://dev.to/nengdev/i-built-a-browser-based-cbz-to-pdf-converter-that-keeps-comics-private-330n <h1> I built a browser-based CBZ to PDF converter that keeps comics private </h1> <p>Recently, I wanted to convert some CBZ comic files into PDF.</p> <p>The usual solution was simple:</p> <p>Upload the file → wait → download the PDF.</p> <p>But there was one problem.</p> <p>Comic archives can easily become hundreds of megabytes, and uploading a personal comic collection to an unknown server didn't feel like the right solution.</p> <p>So I built Mangavia.</p> <h2> What is CBZ? </h2> <p>CBZ is a popular comic book archive format.</p> <p>Technically, a CBZ file is a ZIP archive containing comic page images.</p> <p>Example:</p> <p>comic.cbz<br> ├── 001.jpg<br> ├── 002.jpg<br> ├── 003.jpg<br> └── ...</p> <p>Because CBZ files are basically image collections, they can be processed directly in the browser.</p> <h2> Processing comics locally </h2> <p>Mangavia converts CBZ files completely inside your browser.</p> <p>The process:</p> <ol> <li>Read the CBZ archive</li> <li>Extract comic pages</li> <li>Sort images in the correct order</li> <li>Generate a PDF</li> <li>Create the download file</li> </ol> <p>Your comic files never leave your device.</p> <h2> Why browser-based? </h2> <p>For this type of tool, a server is not always necessary.</p> <p>Local processing provides:</p> <ul> <li>Better privacy</li> <li>No upload waiting time</li> <li>No storage limitations</li> <li>A simpler user experience</li> </ul> <p>Modern browsers are surprisingly powerful.</p> <h2> Challenges </h2> <p>The hardest parts were not only generating the PDF.</p> <p>The challenging areas were:</p> <ul> <li>Handling large CBZ archives</li> <li>Keeping page order correct</li> <li>Supporting different image formats</li> <li>Managing browser memory usage</li> </ul> <h2> What's next? </h2> <p>The current version focuses on simple CBZ to PDF conversion.</p> <p>Future improvements include:</p> <ul> <li>Batch conversion</li> <li>Better comic collection workflows</li> <li>More reading-friendly options</li> </ul> <h2> Try Mangavia </h2> <p><a href="https://cbztopdf.com" rel="noopener noreferrer">https://cbztopdf.com</a></p> <p>I would love to hear feedback from comic readers and developers.</p> webdev javascript privacy showdev