Most online converters work the same way: verify you are human, upload your file to a remote server, wait for processing, and download the result.
But for developers, lawyers, and anyone dealing with sensitive contracts or personal data, "uploading" is a dealbreaker.
The Problem with "Free" Online Tools
When you upload a PDF to a standard converter, you are essentially trusting a black box.
- Where is the server? Is it in a GDPR-compliant region?
- Is it encrypted? Many sites use basic HTTP or weak encryption.
- Is it deleted? Some services delete files after an hour. Others keep them for "machine learning training."
For a quick meme, this doesn't matter. For a bank statement or a client NDA, it matters a lot.
The UnitMaster Solution: WebAssembly (WASM)
We built UnitMaster with a simple rule: Your data never leaves your device.
We achieved this using WebAssembly. WASM allows us to run high-performance code (like C++ image processing libraries or Rust PDF engines) directly inside your web browser.
When you use our PDF to Word converter:
- The Tesseract OCR engine loads into your browser's memory.
- Your PDF is rendered on a hidden HTML5 Canvas.
- The text extraction happens on your CPU.
- The final file is generated in your RAM and downloaded.
At no point does the file travel over the internet. You can even turn off your Wi-Fi after the page loads, and the tool will still work.
Why "Privacy-First" Matters for Developers
As developers, we often need quick tools—JSON formatters, base64 decoders, image resizers. But we also paste API keys, config files, and customer data into these tools.
Using a local-first tool like UnitMaster safeguards you against accidental leaks. It's the utility of the cloud, with the security of a desktop app.
Try It Yourself
Check out our Watermark Remover or Image Converter. Open your browser's Network tab. You will see zero upload requests.
That is the power of local-first software.