How to verify your files aren’t uploaded

We say your files are never uploaded, but you don’t have to take our word for it. Anyone can check with these three methods.

Last updated: 2026-10-03

Method 1: watch network traffic in developer tools

Open any tool page in desktop Chrome or Edge, press F12 (Option + Command + I on a Mac) to open developer tools, and select the “Network” tab.
Drop a file into the tool and watch the list of requests.
You’ll see the site’s own files plus requests to Google Analytics and Google ads. These either download content or send a few hundred bytes of statistics, never your file. To be thorough, type “method:POST” in the filter box to show only requests that send data, and open each one’s “Payload” tab.

Open a tool page and let it finish loading. Some formats such as HEIC download a processing component on first use, so try one image first.
Turn off Wi-Fi or switch on airplane mode.
Process more files. The tool keeps working, which shows the processing happens on your device, not on a remote server.

Uploading a 100 MB file takes a while. In KESI, large files are processed almost instantly, regardless of your connection speed.

Google Analytics: aggregate page-view data only, never file contents. You can decline it via “Cookie settings” in the footer.
Google AdSense: loads and displays ads, never your file contents.
Lunar calendar tool (Chinese pages): sends the date you look up to the Hong Kong Observatory for verification.
First use of some tools: a processing component is downloaded from this site to your browser. That’s a download of code, not an upload of your files.

If you ever see anything that looks like a file upload, please email contact@cpsoho.net and we’ll investigate right away.