Ask HN: Should I translate my website?

I run a website that is a simple tool for a certain task. Right now it is available in english only. It attracts half a million visitors a month. It's mainly word of mouth, press and social traffic. Since it's a tool, there is no text content. So I only rank for very few keywords in search engines. Do you think I should translate the page in all languages? It contains only few words, so it would be easy. I could have a french version at fr.mysite.com, a portuguese version at pt.mysite.com etc etc. Have you made good experiences with this?