How we process your files
Short version: for every tool marked "Runs in your browser", the file is opened by JavaScript running on your device, transformed there, and offered back to you as a download. It is never transmitted to ToolFlint.
What happens when you drop a file
- Your browser reads the file into memory using the File API. No network request is made.
- The page has already downloaded the tool code (a few hundred kilobytes of JavaScript and WebAssembly). That code decodes the file, applies your options and encodes the result.
- The result is turned into a Blob and a download link is created with
URL.createObjectURL. Clicking "Download" saves it from memory to disk. - When you leave the page, the memory is released. Nothing is stored.
How to verify this yourself
Open the tool page, then disconnect from the internet (airplane mode works). Drop a file and run the tool. It still works, because there is nothing to send. Alternatively, open your browser's developer tools (F12), go to the Network tab, and run a tool: you will see no upload request.
Server-assisted tools
A small number of tools, such as speech-to-text or AI image generation, need models that are too large to run in a browser. These are clearly marked "server-assisted" on the page. For those, the file is sent over HTTPS to our processing service on Cloudflare's network, handled in memory, and discarded immediately after the result is returned. We keep no copies and no logs of file contents.
What we do collect
Anonymous, cookieless page-view counts (which pages are visited, from which country, on which browser), so we know which tools to improve. If advertising is enabled, our ad partner sets its own cookies subject to your consent choice. See the privacy policy.