This is a free site where anyone can romanize hangul characters. Anyone may find it useful especially for those who want to sing-along with Kpop lyrics. One must have the copy of the lyrics, (copy then paste it to this site), and it will do its job.
I've used this a hundred times whenever I want to post something in Hangul. You should know the spelling of the word in Hangul in order to convert it correctly. I'm not recommending it for long text conversion. I do not know any other site, thus I never tried another service. Check it out, and see if it'll work for you. Goodluck!