Online Tool Privacy: Why Browser-Based Processing Matters

Where Do Your Uploaded Files Go?

Traditional online tools

Your file → Upload to server → Server processes → Returns result
                ↑
         File stored on server!

The server receives your original file and can store, analyze, or sell your data.

ToolsKu's approach

Your file → Stays in browser → Browser processes → Result generated locally
                ↑
         File never leaves your device!

Technical Foundation

File API + ArrayBuffer

Read files directly into browser memory without network transfer.

WebAssembly (WASM)

High-performance C/Rust programs compiled to run in the browser at near-native speed:

ToolKu Feature	WASM Library	Performance
PNG compression	OxiPNG (Rust→WASM)	Near desktop software
Video transcoding	FFmpeg (C→WASM)	Handles 1080p video
OCR	Tesseract (C++→WASM)	Chinese & English

Web Crypto API

Browser-native encryption — keys and data never leave the browser.

How to Verify Safety

Open DevTools (F12) → Network tab
Use the tool to process a file
Check for upload requests — ToolsKu has none!

ToolsKu Privacy Architecture

Category	Processing	Tools
PDF tools	100% local	Merge, split, rotate, watermark, encrypt
Image tools	100% local	Compress, convert, crop, watermark, OCR
Video tools	100% local	Convert, cut, compress, GIF
Text/JSON	100% local	Format, diff, convert
Encryption	100% local	AES, RSA, SM2/SM3/SM4

PDF-to-Word uses Alibaba Cloud DocMind API and clearly notifies users about the upload.

Common Misconceptions

HTTPS ≠ safe: It only encrypts transit, doesn't prevent server storage
Popular ≠ safe: Many popular tools still upload files to servers
Base64 ≠ encryption: It's just encoding, anyone can decode it

Summary

Privacy should be your primary concern when choosing online tools. ToolsKu processes everything locally using File API, WebAssembly, and Web Crypto API — no uploads, no registration, 200+ tools for PDF, images, video, text, JSON, encryption, and more.