I Built a Browser-Based PDF Converter to Stop Uploading Sensitive Files to Random Sites Tags: #showdev #webdev #javascript #privacy

After uploading what felt like the 100th sensitive contract to a "free" PDF site, I realized I had no idea where those files were going. So I built BunnyConvert — 24 PDF tools that run entirely in your browser using JavaScript.

What It Does

24 tools so far:

• Sign PDF (with cursive fonts, drag-to-position)
• Merge / Split / Compress / Rotate
• JPG/PNG/HEIC → PDF
• PDF → Word/Excel/PowerPoint/Image
• Watermark, Protect, Unlock
• Image Resize, CSV ↔ JSON

The Stack

• Vanilla JS frontend (no React/Vue)
• pdf-lib for PDF manipulation
• pdf.js for rendering
• heic2any for HEIC decoding
• Capacitor for Android wrapper
• Supabase for opt-out analytics

Privacy First

Everything runs client-side. Files never touch a server. You can verify in DevTools Network tab — zero outbound file requests.

Tricky Parts

1. pdf-lib's StandardFonts don't support Turkish characters → had to embed custom TTF
2. DocuSign-like signature placement in vanilla JS with both touch + mouse drag
3. AdMob production approval is brutal for new publishers (~2-4 weeks of "limited ad serving")

Try It

Web: https://bunnyconvert.com
Android: Google Play (search BunnyConvert)
iOS: in submission

Free with daily credits. Pro is $4.99/mo for unlimited + ad-free in mobile.

Open to feedback or questions.