* https://kanji.garden/
* https://www.readthekanji.com (includes hiragana and katakana as well)
You can also use the following for just memorizing hiragana and katakana:
* https://djtguide.neocities.org/kana/
* https://www.kana.pro/
And then there are online resources like the following that provide a guided, DIY approach to learning Japanese as a whole:
* https://www.tofugu.com/learn-japanese/
* https://guidetojapanese.org/learn/
* https://docs.google.com/document/d/10bRzVblKVOsQJjTc2PIi1Gbj...