Hey y’all. I have been searching for a dictionary that will tell me if a word is conversational, formal, literary, etc. for a while now. WaniKani teaches mostly really great words. In fact, I run into a lot of them in books I read or in general around Japan. The issue is I don’t know if I can use them in conversation or not. My current method is usually to just use those words with my boyfriend and see if he corrects me, or just straight up ask him if the word is conversational or not. I can only assume how annoying that must be for him though, so I keep it to an absolute minimum. I was hoping someone knew of some kind of resource that I could use to figure this out on my own without always having to rely on him, friends, or co-workers. Sorry if this has been asked before and was already answered. I tried looking but I could not find anything, but if it has please let me know. 
I do not know about “offline” dictionaries but for online services
- jpdb.io gives you the “top X” info on the right
- You can setup Yomitan with a frequency dictionary
Recommended frequency dictionaries
Yomitan supports the use of frequency dictionaries that tell you how common a word is.
JPDB - A frequency list made from jpdb.io, which is a site that has analyzed many light novels, visual novels, anime and j-drama. In turn, this is a frequency list from Japanese fictional media.
CC100 - Frequency list of corpus data from Japanese internet. Formal words will appear more common in this frequency list . Example: 審議会 (council) is 9733 frequency on CC100 and 58730 on JPDB.
What is a common word?
Very common: 1-10,000
Commmon: 10,001-20,000
Fairly common: 20,001-30,000
Kind of uncommon: 30,001-40,000
Uncommon: 40,001-50,000
Rare: 50,001-80,000
Natives-probably-don’t-know-it-level: 80,000+
Also the Userscript
Uses several frequency list but here consulting them though the right tooling is the challenge.
Oh this is cool stuff. I will have to check it out thank you!