Hiragana
Katakana
This tool makes no network requests and can be used totally offline! Just highlight some Romaji
text, right click and select the dialect of writing you would like to see it turn into. The changes on the page are non-permanent and refreshing the page will cause the text to return back to its original form.
The functionality and library that makes this possible is from: http://whiteagle.net/. Their efforts make this tool possible.
Thank you, -Tim