Data sources & licenses

The public credits page. Several of these licenses (CC BY / CC BY-SA) legally require attribution — this page satisfies that. Use the ふりがな pill to toggle furigana on the Japanese source names.
arrow_back Data sources & licenses 出典

Nihongo is built on open data and open-source software. We're grateful to the projects and contributors below. Where a license requires it, we credit the source here and in Settings → Data sources & licenses.

verified
Facts come from verified data, not AI. Readings, meanings, JLPT levels, furigana, stroke order and conjugations are taken from the curated sources below. AI is used only to generate language (level rewrites, example sentences, explanations) — never to invent facts.
newspaperReading content — News
Japanese government & ministry press releases政府標準利用規約 2.0
Leveled news articles, rewritten by us into 5 difficulty levels (N5–N1). Sources include , , , , , and others.
Obligation: credit the issuing agency and indicate that the article was adapted/abridged. The (Standard Terms of Use, v2.0) is compatible with CC BY 4.0. Each agency's own terms are re-checked at ingest.
· Japan Meteorological AgencyCC BY 4.0 互換
Weather and disaster-prevention () information for the 気象 / 災害 news tabs, from the JMA disaster-prevention XML feed.
Obligation: credit (JMA). Provided under the JMA website terms, which follow the government Standard Terms of Use (CC BY 4.0-compatible).
Wikipedia (Japanese) — CC BY-SA 4.0
Current-events summaries from the Japanese Wikipedia "Portal:最近の出来事" used as a leveled news source.
Obligation (ShareAlike): credit "Wikipedia contributors," link back to the article and its license, and release our adapted text portion under CC BY-SA 4.0. Our app code, UI and AI features are not affected — only the redistributed text derivative.
ja.wikipedia.org · Portal:最近の出来事 →
auto_storiesReading content — Stories & artwork
· Aozora BunkoPublic domain
Classic literature and folktales (, , …) for the Stories genre, including classical-Japanese (古文) readers.
Obligation: the works are public domain (copyright expired) — free to copy, redistribute and adapt, including commercially. We still credit and the volunteer / (input/proofing) contributors per work, as some digitised files carry the volunteers' own terms.
aozora.gr.jp →
Wikimedia Commons — story artworkPublic domain / CC
Authentic public-domain illustrations of each work used as story cover art (e.g. for 竹取物語).
Obligation: per-image — we show the artwork title, author/source and license tag on or beside the cover, as each file requires.
dictionaryDictionary & kanji data
JMdict / JMnedictCC BY-SA 4.0
Core dictionary entries — readings, meanings, parts of speech (~170k words).
Obligation: credit the Electronic Dictionary Research and Development Group (EDRDG) per the EDRDG License; the redistributed dictionary data stays CC BY-SA.
edrdg.org →
KANJIDIC2CC BY-SA 4.0
Kanji data — on/kun readings, meanings, stroke counts, JLPT level, radicals.
Obligation: credit EDRDG per the EDRDG License (ShareAlike on the data).
KanjiVGCC BY-SA 3.0
Kanji stroke-order data, used to draw the stroke-order animations in the dictionary and the handwriting/draw search.
Obligation: credit Ulrich Apel / KanjiVG; derivatives stay CC BY-SA 3.0.
kanjivg.tagaini.net →
kradfile / radkfileCC BY-SA
Kanji ↔ radical decomposition, powering radical and handwriting search.
Obligation: credit EDRDG per the EDRDG License.
TatoebaCC BY 2.0 FR
Example sentences shown in the dictionary and word-detail pages.
Obligation: credit Tatoeba and its contributors.
tatoeba.org →
schoolGrammar & JLPT data
HanabiraCC BY-SA 4.0
JLPT N5–N1 grammar points (828) used in the grammar reference and grammar practice.
Obligation: credit hanabira.org; any distributed grammar dataset derived from it stays CC BY-SA 4.0 (ShareAlike).
hanabira.org →
tanos.co.uk JLPT listsCC BY
JLPT level tagging for vocabulary (via open-anki).
Obligation: credit the source (Jonathan Waller, tanos.co.uk). Exact CC version verified at build.
Curated slang & idioms© Estate One Company Limited
Our own slang/idiom content — not third-party data.
share
ShareAlike (CC BY-SA) note. The grammar and dictionary datasets carry a ShareAlike obligation for the data itself. Our app code, UI, AI features and other assets remain ours — only the redistributed dataset portion stays CC BY-SA with attribution. Confirm with your attorney how this interacts with distribution.
codeFonts & open-source software
Noto Sans JP · Noto Serif JP · InterSIL OFL 1.1
Japanese and Latin typefaces. Material Symbols icons (Apache 2.0).
Open-source librariesMIT & others
Built with Expo, React Native, React, expo-router, ts-fsrs, kuromoji, react-native-svg, @supabase/supabase-js, @anthropic-ai/sdk and others, under their respective licenses.
A full list of bundled packages and licenses is available on request at support@bynetica.com.
cloudServices we use (disclosed, not "credits")
These power features but do not require attribution. They're listed here for transparency and detailed in the Privacy Policy:
Anthropic Claude — AI text & vision · Google Cloud — text-to-speech & speech recognition · Supabase — database, auth, storage, hosting · Apple / Google — sign-in & in-app payments.
Effective date: June 23, 2026. This list is verified against what the app actually ships before each release; anything no longer used is removed.
Shown in-app at Settings → Data sources & licenses and publicly at bynetica.com/attributions.
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