Most "free" online PDF tools upload your files to their servers. That means your medical documents, salary slips, financial records, and confidential contracts are sitting on someone else's computer. When I built ToolForge's 12 PDF tools, I made a hard decision: nothing leaves the browser. Here's exactly how I built it and what I learned. Why Browser-Only Matters When you compress a PDF on most free tools, here's what actually happens: Your file uploads to their AWS/Google Cloud bucket Server-side code processes it Processed file downloads back to you Your original file sits in their storage (usually deleted after 24h... usually) For a salary slip, medical report, or legal document — this is a real privacy risk. Browser-only processing eliminates it entirely.…