Browser Processing Policy
How the tools process your files without uploading them, in plain language.
Updated
Your browser opens the file, JavaScript on your own device does the work, and the result comes back to you. The file never crosses the internet to us; only library code is downloaded.
The short version
When you use a tool, your browser opens the file, JavaScript running on your own computer or phone processes it, and you get the result. The file never travels across the internet to us, which is why the tools are quick and private.
The technology behind it
- The File API reads the file you pick into the page's memory.
- The HTML5 Canvas handles image resizing, conversion, cropping and filters.
- pdf-lib and PDF.js read and write PDF documents on your device.
- SheetJS and Mammoth.js open spreadsheets and Word documents locally.
- The Web Crypto API creates hashes and secure random values in the browser.
What does leave your browser
To keep pages light, some tools download their library (a code file) from a public CDN, and the analytics services described in the Privacy Policy send page-view data. Those requests carry code and usage counts, never the contents of your file. You can check this yourself in your browser's developer tools.
Limits of browser processing
Because the work happens on your device, your device's free memory caps how large a file you can process, and a few operations that need a server are left out on purpose. For most everyday tasks, processing in the browser is faster and safer than uploading.