Type "compress pdf" into a search engine and almost every result works the same way: you upload the file, a server compresses it, you download the result. For a holiday photo, fine. For a bank statement with your account number, address and salary on it, that is a copy of a sensitive document sitting on a machine you know nothing about.
What actually happens on an upload site
Your file crosses the internet, is written to disk on a server, is processed, and is kept for some period — often an hour, sometimes far longer, sometimes indefinitely if a backup catches it. The company may be reputable. The company may also be a two-person operation renting a virtual machine, or may be acquired, or may be breached.
What browser-based means
Every tool on Filix uses JavaScript running inside your own browser tab. The file is read from your disk into your browser memory, transformed there, and written back to your downloads folder. It never travels. Close the tab and the memory is gone.
You can verify this yourself: open the browser developer tools, go to the Network tab, and run a conversion. You will see the page and its libraries load, and no upload of your file.
What we still record
We are not going to pretend we record nothing. Filix logs the tool used, the name of the file, your IP address, the city it maps to and your browser — so we can see what is popular and what is broken. Never the contents, because the contents never reach us. That is set out in full in our Privacy Policy.
The trade-off
Browser processing uses your device memory, so a 200 MB PDF on an old phone will struggle where a server would not. That is the honest cost, and for sensitive paperwork it is worth paying.