ZapMorph – Private, In-Browser File Converter

ZapMorph is a free online file conversion toolkit that runs entirely in your browser. Your files are processed on your own device and never uploaded to a server, so you can convert sensitive documents without worrying about privacy. What problem it solves Most online converters make you upload files to someone else's server, wait in a queue, and hope your contracts, invoices or personal photos are deleted afterwards. ZapMorph removes that risk. Conversion happens locally, so it's faster, works with confidential files, and doesn't depend on server capacity. What you can do • PDF: convert, merge, split, extract text, and run OCR on scanned documents • Documents: Word (DOCX), Excel (XLSX), CSV, Markdown and HTML conversions • Images: HEIC, TIFF, PNG, JPG and more, including HEIC-to-JPG for iPhone photos • Email: open and convert Outlook MSG, EML and PST files without Outlook • Audio and video: convert media formats in the browser, powered by FFmpeg (WebAssembly) • Developer tools: JSON formatter with a collapsible tree view, YAML/XML converters, text diff, hashing, and a QR code generator • File viewers: preview formats your computer can't open natively How I built it I built ZapMorph as a solo founder alongside my backend job. The main engineering challenge was moving heavy work like OCR, video transcoding and PDF manipulation from the server into the browser. I used WebAssembly builds of FFmpeg and Tesseract, plus on-device ML models, so even demanding conversions run client-side. The site is server-rendered for speed and SEO, with a blog of how-to guides for common file problems. Tech stack • Framework: Next.js 16 (App Router), React 19, TypeScript • Styling: Tailwind CSS v4 • In-browser processing: FFmpeg.wasm, Tesseract.js (OCR), pdf.js, pdf-lib, Mammoth, docx, ExcelJS, Hugging Face Transformers.js • Backend and auth: Supabase (Postgres + Google OAuth) • Payments: Paddle (INR and USD plans) • Email: Resend • Hosting and analytics: Vercel