WaniKani synchronisation bugged

I’ve tried syncing with WK (WaniKani) many times over the last week, and every single time it gives me 3000+ vocab in the highest level. My WK account is only lvl 3 and I’ve spoken with their support staff about if my API key is broken, bugged or not updated, and they say it is. To check it I also used it with wkstats and it accurately stated my level and learned vocabs to be about a hundred.

I would really like to have a clear overview of what vocab I already know from WK and what I can learn here + use the furigana synced to WK progress feature, so I hope this is something that can be worked out.


If you are only level three, it may genuinely not be worth it to synch your vocab, rather just starting from scratch on Bunpro.

No, I plan on using it going forward for kanji since I like their mnemonics (I have a very old lifetime membership)


This just happened to me, too. I am Level 2 on WK, and I now have 3000+ mastered vocabulary on Bunpro after synching. Can someone help us with this problem?

Just like @SebastianLassen said, wkstats correctly shows me as learning only 40 vocabulary so far on WK. So it is not a problem with the WK API.

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Same here. I’m level 14 on WK and it used to work just fine. It’s been broken for me for a long time now. I didn’t notice when exactly the system broke down, but I think it was around the time they introduced kana-only vocab.

I’ve tried with three different browsers + mobile app. None of them works. Tried to generate new API key, doesn’t work. WKstats still works just fine for me too.
When trying to sync nothing happens and after a while I get “503 service unavailable” status error on console.

I think I did once report this in a Bug Reports -thread etc., but it eventually just got buried without answer.


Quick initial question - for those having problems, had you reset your WK account progress previously? Ex: Study on WK > sync with Bunpro > reset their WK account. We’ll take a deeper dive into this tomorrow, but this could potentially help shed some light.


I reset my WK account before ever syncing and it still moved 3450 vocab to masters instantly. I’ve also tried resetting all my vocab progress and doing it over again with a new API key that was confirmed to be working correctly by WK staff, and the exact same result followed.

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I haven’t reset.

I reset my WK a few days ago, and then tried to sync with Bunpro today. I’m Level 2 on WK and now I have 3255 Mastered vocabulary on Bunpro. (I had 0 yesterday)

Thank you @EdBunpro for looking into this for us!


I discovered something interesting related to this bug by switching on the “Content Display → Furigana → Wanikani” setting. This works correctly even though the vocab being moved to masters upon synchronisation with WK is completely wrong.

Hope this helps in finding the bug involving vocab synchronisation

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Oh indeed. Same here!

Following up on this. I have found the source of this and am patching it now. It should be out later today. Thank you to everyone who provided feedback it helped immensely in figuring out why there was a disconnect between what it does and what the expected outcome is.


Mine doesnt sync at all, even though I’ve learnt new stuff.

The change is live.

The best course of action is to use the Wanikani option in the Reset Vocab dropdown here: https://bunpro.jp/settings/reset

This will remove your Bunpro vocab reviews that are covered by Wanikani content.

You can then use one of the Sync options here: https://bunpro.jp/settings/general

  • Sync [Master] will check your Wanikani progress and mark it mastered here on Bunpro. This will work be triggered for all of your Wanikani progress regardless of its streak on Wanikani. You may earn a lot of xp.

  • The other option (Sync Practice) will check what Wanikani content you have studied up to Guru. For each one, it will create a Seasoned review here on Bunpro (SRS 7). This was a requested feature to get a little more practice with Wanikani vocab in context.

    These reviews will be due now. This means you might have quite a few vocab reviews added, so use this with caution.

Thank you to everyone who provided feedback it helped us figure out what needed changing!

If you have any feedback on this change or questions, please don’t hesitate to ask :bowing_man:


Thank you @Jake! I just tried it out, and it works as advertised :+1:

I planned to stay away from the “Mastered” option, but I do love the “Practice” option. I agree that getting more practice on the sentence context of the words from Wanikani is a huge help. Thanks so much!


Works perfectly now and the practice feature is nice :bowing_man: As an aside, does Bunpro automatically keep syncing with WK progress or do you have to sync it as you make big progress over there?


I’ve noticed a new issue. This solution worked great and I was able to sync new words as I progressed with Wanikani. Until I went through my vocab decks and manually marked few words as Mastered. (There’s a lot of words I know already but haven’t yet encountered in WK.) After that the syncing feature stopped working immediately.

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I have the same question, and haven’t really found the answer anywhere as to whether I have to go and regularly click the Sync [Practice] button or whether it will do so automatically (once a day for example). I think the furigana setting updates automatically as you progress through WK, but I’m not sure about this the vocab practice.

WaniKani sync is broken for me too, endpoint returns a 503. I also manually mark mastered words as well. I’m deep into WaniKani and the sync feature is incredibly useful to optimize new vocabulary on Bunpro so I would greatly appreciate it if someone can look into this.

Hi, I tried to looking into this today and the option to Reset Vocab is no longer available on the reset section.