Tell us what broke
Bug reports and converter requests are read. Include the tool name, your browser and what you expected to happen — that is usually enough to fix it.
Send a message
Before you write
A conversion produced a broken file
Note the tool, the input format and the settings you used. Try the same file in a different browser — if it works there, tell us which browser failed.
The page will not load a tool
Usually a blocked script or an outdated browser. Disable extensions for this site and reload. The PDF tools need WebAssembly, which every current browser supports.
Can you convert a format that is not listed?
Ask. Formats that can be handled safely in the browser are the ones that get added.