This is probably subjective, but what is the best online Japanese (kanji) dictionary?

I would say the beta version of Denshi Jisho for J-E.

http://beta.jisho.org/

For J-J I usually use Goo Jisho:

http://dictionary.goo.ne.jp/

You should also use Rikaisama, which works in both J-E and J-J mode (or as a kanji reader without definitions)

https://kawaiijapanese.wordpress.com/201...ma-review/

Thanks for your reply. The Jisho dictionary seems to be what I was looking for as a resource to cross reference individual kanji readings.

It's probably no use for kanji readings, but it's worth noting Excite辞書 since it's the only one I've found online that reliably has the accent codes. The iOS version of 大辞林 (what Excite is using) has accent codes too, but other versions like Yahoo!'s one don't.