I used to have a website, but I let it die, because 1) it costs money 2) nobody was looking at

So keep in mind where somebody is providing an abc converter, somebody must be paying to store it on a server somewhere and to provide the thing on request by your browser. Sometimes a little gratitude expressed will nudge them to keep it running another month :)

For the simple minded like me, a program that runs on your own computer and does not depend on the net at all might be better.