I built 60+ free image and PDF tools that run entirely in your browser - here's why and how

Every time I needed to compress a PNG, convert a HEIC photo from my iPhone, or merge a couple of bank statement PDFs, I'd run into the same wall:

• The tool wants my email
• The output has a watermark
• There's a daily limit of 3 files
• My file gets uploaded to a server I've never heard of

For a screenshot, fine. For a contract or a scan of my ID — absolutely not.

So I built AI PixFix — a collection of 60+ image and PDF tools that run entirely in the browser. Files never leave your device, there's no sign-up, no watermark, no quota.

The stack (it's surprisingly small)

Almost everything is plain browser APIs. No backend processing:

• Image conversion / resize / crop / compression — <canvas> and OffscreenCanvas, with canvas.toBlob() for output
• HEIC decoding — libheif-js (WebAssembly port of libheif)
• AVIF decoding/encoding — native browser support in Chrome/Firefox/Safari (no library needed in 2026)
• PDF read/write/merge/split — pdf-lib for editing, pdf.js for rendering
• Background removal — an on-device ONNX model (@imgly/background-removal) running in a Web Worker
• Vectorization (raster → SVG) — ImageTracer.js running client-side
• Word ↔ PDF — mammoth for .docx parsing + canvas-based rendering

Total backend code I had to write for the conversion pipelines: zero lines. Everything is the browser.

Why "browser-only" is a real feature, not just a privacy talking point

I assumed people would care about the privacy angle. They do — but the bigger win turned out to be:

1. Speed. No upload, no download. Drag a 50 MB PSD in, get the result in ~3 seconds. Most cloud tools spend the bulk of their time on the network round-trip.
2. No artificial limits. When the conversion costs me $0 in compute, there's no reason to put a "3 files per day" cap on it.
3. Offline mode. Once the tool's JS is cached, it works on a plane.

What I learned about marketing a tool collection

A few non-obvious things:

• Programmatic SEO works. Each "X to Y" converter (PNG to JPG, HEIC to PNG, AVIF to WebP, ...) is its own page targeting a specific long-tail query. ~50 of these now drive most of my traffic.
• The "no sign-up" message in the H1 converts better than feature lists. People are exhausted by signup walls.
• Internationalization compounds. Adding Spanish translations roughly doubled my non-US impressions in 4 weeks.

Try a few

If you want to see what 60+ tools running in your browser looks like:

• 😂 Make a meme — pick a template, add top/bottom text, download as PNG
• 📷 Convert HEIC to JPG — for those iPhone photos that won't open on Windows
• 📦 Compress images — usually 60-90% smaller, no visible quality loss
• 📑 Merge PDFs — drag, reorder, download
• ✍️ Sign a PDF — draw your signature, place it, save. Never leaves your device.
• 🎨 Image to SVG — vectorize logos and icons

Or browse the full collection at aipixfix.com.

If you've built something similar — or if you're stuck on the "everything in the browser" approach for a specific format — happy to compare notes in the comments.