Lexi
Scroll German. Save a word. Lexi makes it stick.
A free, open-source German vocabulary app for English speakers: 10,000+ words from
A1 to C2 to learn, and a dictionary of 93,000+ headwords to look things up in. No account,
no ads, nothing to cancel — and your progress stays on your device.
Open Lexi → — it runs in the browser; add it to your
home screen and it works offline.
Who it is for
English speakers living with German — past the course, somewhere between A2 and B2,
who want to read the news and the letter from the Ausländerbehörde without a
dictionary open. It works from A1, but Lexi teaches words, not grammar: if you are
starting from zero, use it beside a course, not instead of one.
What makes it different
- Nothing to pass. Lexi opens on a German word, not a quiz: one word per screen,
with its sound, its meaning and an example, and nothing is graded until you ask.
Every few words there is a German news story on topics you choose (tagesschau, SRF,
DW, heise), fetched by your own browser — tap any word in it to save it.
- You choose what you learn. Save a word and Üben (practice) brings it back
just before you would forget it — FSRS spaced repetition. Cards say why they are in
front of you, and recognising a word and producing it (typed, article included) are
scheduled separately, because recognising is only half of knowing.
- Checked, not generated. Gender, plural, part of speech and pronunciation come
from Wiktionary, never from a model, and a new card is refused outright if any of them
disagrees with de.wiktionary or its example sentence does not contain the word.
- Lexi in your ears. Walk turns a session into audio for a walk or a run, 5 to 60
minutes: hear the English, say the German aloud, then hear it. You grade with your
headphone buttons; silence grades nothing, and your voice is never scored.
- Your German, as a sky. Every word Lexi teaches is a star, the commonest at the
centre, and the ones you know are lit as brightly as you would recall them today.
Share it — the picture carries the link.
- Yours. No account, no tracking, no ads. Progress lives in your browser's storage
(back it up from Settings). An optional tutor explains sentences on your own AI key,
and is off until you add one. The code is MIT; the corpus is CC BY-SA, every source
recorded in
ATTRIBUTIONS.md.
How it compares
Lexi is small on purpose. What the others do better is real, and worth saying:
| If you use… | it is better at… | Lexi is different because… |
|---|
| Duolingo | a whole course — grammar, listening, speaking — as a daily game | it is only vocabulary, for adults, with no game to win or lose, and it goes deep at B1–C1 |
| Anki with a shared deck | anything, in any language, exactly your way | there is no deck to build or debug, and every gender and plural is checked |
| LingQ, Readlang | reading any text you bring | a word counts as known when the scheduler's evidence says you would recall it, not when you mark it — and it is free |
What Lexi deliberately does not do — teach grammar, mark your speech, run leagues,
or say "you can now…" from a word count. Ruled 2026-09-05: a drill earns its place
if it tests a property of the word (gender, plural, spelling, the German you have
to produce) and goes if it tests a rule of the language. Every gloss is in
English; other language pairs are an architectural goal, not a shipped feature.
docs/VISION.md carries the whole argument, including what it would
take to reverse each refusal.
Docs
docs/VISION.md is the anchor — what this is, what it refuses, and
what is still undecided. docs/BACKLOG.md is what's next;
docs/CHANGELOG.md is what shipped and why. Full index at
docs/README.md.
What's inside
Measured against the shipped corpus on 2026-09-26. The two headline counts are
guarded by src/lib/publicCopy.test.ts, which fails when the corpus outgrows them.
- 10,000+ word cards across all six CEFR levels, every one with at least two
usage examples, German and English, and all but a handful with IPA.
- Cards carry a gloss, gender and plural, synonyms and antonyms, word family and — from
B2 — a German-language definition.
- 93,000+ dictionary headwords answer what the cards do not, kept visibly apart:
an entry is an unverified Wiktionary gloss you can look up and note, never study.
- 274 topic sectors, rolled up into broad theme groups for browsing and the heatmap.
- FSRS scheduling via
ts-fsrs. Every drill mode is its own track, so recognising
a word and producing it are scheduled separately — that split is what makes the
recall drill honest.
- Local-first: progress lives in IndexedDB with export/import for backup and moving
between machines.
Surfaces
Four destinations, and the first one is where the app opens.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
