If you're using any characters beside those uses in 7-bit ASCII you'll have to think about character encodings. The easiest thing nowadays is usually to make every subsystem use UTF-8. To make Ruby use UT8 add $KCODE="UTF8" to app.rb. Make sure to add it all the way at the top, before loading Nitro. Then "charset=utf-8" will be added to the headers of a html response. If you set $KCODE after requiring Nitro this does not work!