The latest articles on DEV Community by Gabriel Donat (@gabriel_donat_bba978c082c). https://dev.to/gabriel_donat_bba978c082c https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3982855%2F313827d1-42fe-4823-bef1-b01ba56313dc.png https://dev.to/gabriel_donat_bba978c082c en Gabriel Donat Sat, 13 Jun 2026 15:24:21 +0000 https://dev.to/gabriel_donat_bba978c082c/i-built-a-document-converter-that-never-uploads-your-files-11gm https://dev.to/gabriel_donat_bba978c082c/i-built-a-document-converter-that-never-uploads-your-files-11gm <p>Every time you use an online PDF converter, your file travels to a server somewhere — processed by a company you don't know, stored temporarily on hardware you don't control.</p> <p>For a random meme? Fine. For a payslip, a contract, or a medical document? That's a real privacy problem.</p> <h2> What I built </h2> <p><strong>ConvertiZen</strong> is a document converter that runs 100% in the browser using WebAssembly and modern JS APIs. Your file never leaves your device. Ever.</p> <p>Verify it yourself: open DevTools &gt; Network tab &gt; run a conversion. Zero outgoing requests containing your file data.</p> <h2> What it supports </h2> <p>40+ format pairs:</p> <ul> <li>PDF ↔ Word, JPG, PNG, Text, HTML, Markdown</li> <li>Excel ↔ CSV, JSON, HTML</li> <li>Images: JPG ↔ PNG ↔ WebP, GIF/BMP → PDF</li> <li>JSON ↔ CSV, Markdown ↔ HTML, XML → JSON</li> </ul> <h2> How it works </h2> <ul> <li> <strong>PDF.js</strong> for PDF parsing</li> <li> <strong>docx</strong> library for Word generation</li> <li> <strong>SheetJS</strong> for Excel/CSV</li> <li> <strong>Canvas API</strong> for image conversions</li> <li>Everything client-side — no server required</li> </ul> <h2> Pricing </h2> <p>3 free conversions/day, no account needed. Beyond that: €0.69/conversion, €4.99 for a pack of 10, or €4.99/month for unlimited Premium.</p> <h2> Feedback welcome </h2> <p>What formats are missing? What would make you trust a browser-based tool over a server-based one?</p> <p>👉 <a href="https://convertizen.netlify.app" rel="noopener noreferrer">https://convertizen.netlify.app</a></p> webdev javascript privacy showdev