Duolingo JA from EN versions:

Trees:
v0: 2017-02-02  ? (Beta)
v0: 2017-10-11  ? (Beta)
v1: 2018-02-12, 40 Skills (40 Different lessons)
v?: 2018-05-17, 66 Skills (66 Different lessons)
v?: 2018-12-05, 87 Skills (57 Different lessons)
v?: 2019-07-29, 92 Skills (92 Different lessons)
v?: 2019-10-10, 121 Skills (121 Different lessons)
v4: 2020-01-09, 131 Skills (131 Different lessons)
v?: 2020-10-10, 142 Skills (142 Different lessons)
v15: 2020-11-01, 136 Skills (136 Different lessons)
v16: 2021-06-09, 169 Skills (169 Different lessons)

Paths:
1.0: 2022-09-10, 131 Skills (131 Different lessons) (90 units)
1.1: 2022-11-01, 131 Skills and 30 Stories = 161 Different Lessons (90 units)
2.0: 2023-02-20, 169 Skills (169 Different lessons) (125 units)
2.1: 2023-09-01, 169 Skills and 30 Stories = 199 Different Lessons (125 units)
3.0: 2023-09-10, 193 Skills and 30 Stories = 223 Different Lessons (121 units)
3.1: 2023-05-01, 194 Skills and 30 stories = 224 Different Lessons (212 units) [Schools]
3.2: 2024-05-10, 194 Skills and 29 stories = 223 Different Lessons (186 units) [Schools]

CEFR:
1.0: 2023-10-10, 193 Skills and 30 stories = 223 Different Lessons (212 units, CEFR A1)
1.1: 2023-10-10, 283 skills and 30 stories = 313 Different Lessons (212 units, CEFR A1)
1.2: 2023-12-15, 283 skills and 30 stories = 313 Different Lessons (143 units, CEFR A1)
2.0: 2024-04-22, 283 Skills and 30 stories = 313 Different Lessons (252 units, CEFR A2)
1.3: 2024-05-01, 283 Skills and 30 stories = 313 Different Lessons (252 units, CEFR A1)
2.1: 2024-05-18, 283 Skills and 29 stories = 312 Different Lessons (221 units, CEFR A2)
2.2: 2024-08-01, 283 Skills and 30 stories = 313 Different Lessons (221 units, CEFR B1)
2.3: 2024-10-16, 283 Skills, 30 stories, 91 radios, 38 adventures = 442 Different Lessons (221 units, CEFR B1)
2.4: 2025-06-01, 283 Skills, 30 stories, 218 radios, 38 adventures = 569 Different Lessons (221 units, CEFR B1)
2.5: 2025-07-03, 283 Skills, 30 stories, 218 radios, 38 adventures = 569 Different Lessons (221 units, CEFR B1)
2.6: 2025-09-01, 283 Skills, 29 stories, 218 radios, 38 adventures = 568 Different Lessons (221 units, CEFR B1)
2.7: 2025-10-10, 283 Skills, 29 stories, 223 radios, 38 adventures = 573 Different Lessons (221 units, CEFR B1)
3.0: 2026-03-05, 1030 Skills, 31 stories, 175 radios, 190 kanji = 1426 Different Lessons (1030 units, CEFR B2)
3.1: 2026-04-30, 1030 Skills, 999 stories, 575 radios, 226 kanji = 2830 Different Lessons (1030 units, CEFR B2)

Edited by Mat!/Ozone, 2026/05/16.