There is now a set of small utilities at tools. They are free, there is no sign up, and there is no catch to explain.
They compute in your browser. That is not a privacy promise made in a paragraph, it is how they are built: every route in the suite is a GET, and there is deliberately no endpoint that accepts your input at all. Whatever you paste into one of these never leaves the machine you are sitting at.
If one of them is useful to you, use it. If one is missing, say so.