The latest articles on DEV Community by hwlsniper (@hwlsniper). https://dev.to/hwlsniper 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%2F3952557%2F14366364-ccb4-4228-8924-6836c5332164.png https://dev.to/hwlsniper en hwlsniper Tue, 26 May 2026 15:17:12 +0000 https://dev.to/hwlsniper/i-built-a-free-pdf-toolbox-that-runs-entirely-in-your-browser-zero-uploads-4e4h https://dev.to/hwlsniper/i-built-a-free-pdf-toolbox-that-runs-entirely-in-your-browser-zero-uploads-4e4h <h2> Why I Built It </h2> <p>I needed to compress a PDF last week. The first 5 Google results all required uploading my file to a server. Some wanted my email. Others limited me to 2 files per day.</p> <p>I'm a developer. I thought: <em>we have WebAssembly, Web Workers, and the File API — why are we still uploading PDFs to random servers?</em></p> <p>So I built <a href="https://pdftoolbox-three.vercel.app" rel="noopener noreferrer">PDF Toolbox</a> — a collection of PDF tools that process everything <strong>locally in your browser.</strong></p> <h2> What It Does </h2> <ul> <li> <strong>Compress PDF</strong> — reduce file size while keeping quality</li> <li> <strong>Merge PDF</strong> — combine multiple PDFs into one</li> <li> <strong>Split PDF</strong> — extract pages or split into individual files</li> <li> <strong>PDF to JPG</strong> — convert each page to an image</li> <li> <strong>JPG to PDF</strong> — bundle images into a PDF</li> <li> <strong>Unlock PDF</strong> — remove password protection (if you know the password)</li> </ul> <h2> Tech Stack </h2> <p>Built with <strong>Next.js 16 + TypeScript + Tailwind CSS</strong>, deployed on Vercel. The PDF processing uses client-side libraries so files never touch a server. Every tool works offline once the page is loaded.</p> <h2> Design Decisions </h2> <h3> Privacy-first architecture </h3> <p>This was my number one constraint. All PDF processing runs in the browser using the Web Worker API. When you drop a file, it stays in your browser's memory — nothing is sent to any backend. You can turn off your internet connection after the page loads and everything still works.</p> <h3> No limits, no registration </h3> <p>Most PDF tools gate features behind accounts or daily limits. PDF Toolbox has no concept of users — there's no database, no login, no tracking. Use it as many times as you want.</p> <h3> Simple UI, complex backend </h3> <p>I kept the interface dead simple: drag-and-drop, one-click processing, instant download. But under the hood there's a lot going on — streaming file reads, memory-efficient processing for large PDFs, and proper error handling for edge cases like encrypted files and corrupted PDFs.</p> <h2> What's Next </h2> <ul> <li> <strong>PDF to Word</strong> — coming soon</li> <li> <strong>Watermark PDF</strong> — add text/image watermarks</li> <li> <strong>Dark mode</strong> — working on it</li> <li> <strong>Mobile PWA</strong> — installable offline app</li> </ul> <h2> Try It Out </h2> <p>Head over to <a href="https://pdftoolbox-three.vercel.app" rel="noopener noreferrer">pdftoolbox-three.vercel.app</a> and try compressing a PDF. No signup, no upload, no catch.</p> <p>I'd love feedback from the Dev.to community! What PDF features would you find most useful? Drop a comment below.</p> webdev tutorial javascript ai hwlsniper Tue, 26 May 2026 13:04:15 +0000 https://dev.to/hwlsniper/i-built-a-privacy-first-pdf-toolbox-your-files-never-leave-the-browser-1kn4 https://dev.to/hwlsniper/i-built-a-privacy-first-pdf-toolbox-your-files-never-leave-the-browser-1kn4 <p>Every online PDF tool I've used uploads your documents to their servers. Tax returns, contracts, medical records — they all go to some third-party server for processing. That bothered me enough to build an alternative.</p> <p><a href="https://pdftoolbox-three.vercel.app" rel="noopener noreferrer">PDF Toolbox</a> is a set of PDF tools where <strong>everything runs locally in your browser</strong>.</p> <h3> How it works </h3> <ol> <li>You select a PDF file</li> <li>The file loads into browser memory (ArrayBuffer)</li> <li>pdf-lib processes it entirely in the browser</li> <li>You download the result</li> </ol> <p>The file never leaves your computer. No upload. No server. No privacy risk.</p> <h3> Features </h3> <ul> <li>Compress PDF (reduce file size)</li> <li>Merge multiple PDFs into one</li> <li>Split PDF into individual pages</li> <li>Convert PDF to JPG images</li> <li>Convert JPG images to PDF</li> <li>Unlock password-protected PDFs</li> </ul> <h3> Why I built it </h3> <p>I handle sensitive documents regularly and the thought of uploading them to random servers makes me uncomfortable. With WebAssembly and modern PDF libraries like pdf-lib, there's no technical reason PDF tools need server-side processing anymore.</p> <h3> Tech Stack </h3> <ul> <li> <strong>Next.js 16</strong> with App Router</li> <li> <strong>pdf-lib</strong> for PDF generation and manipulation</li> <li> <strong>pdfjs-dist</strong> for PDF rendering</li> <li> <strong>Tailwind CSS 4</strong> for styling</li> <li> <strong>Vercel</strong> for hosting</li> </ul> <h3> Try it out </h3> <p><a href="https://pdftoolbox-three.vercel.app" rel="noopener noreferrer">PDF Toolbox</a> — completely free, no registration, no limits.</p> <p>Feedback and feature requests welcome!</p> <p><em>GitHub: <a href="https://github.com/hwlsniper/pdftoolbox" rel="noopener noreferrer">github.com/hwlsniper/pdftoolbox</a></em></p> opensource webdev javascript tutorial