I Built a Free Browser-Based PDF Merger That Never Uploads Your Files

Every time I need to merge PDFs, the same thing happens. I Google "merge PDF online," click the first result, and get hit with: "Upload your files to our secure server" "Free for files under 5MB" "Sign up to download" No thanks. I deal with contracts, invoices, and project docs regularly. I don't want any of that sitting on someone else's server, even temporarily. So I built my own PDF merger that runs 100% in your browser. No uploads. No servers. No accounts. How It Works The tool lives at devtools-site-delta.vercel.app/pdf-merge and uses pdf-lib, a pure JavaScript library that can create and modify PDF documents entirely client-side. Here's the core idea. When you drop files into the tool, it reads them as ArrayBuffers using the File API, then pdf-lib stitches them together: import { PDFDocument } from 'pdf-lib'; async function mergePDFs(pdfFiles) { const mergedPdf = await PDFDocument.create(); for (const file of pdfFiles) { const arrayBuffer = await file.arrayBuffer(); const pdf = a