What is DigMyGem? An open-source language reader

DigMyGem is an open-source reader for language learners. You read your own articles, books or subtitles, tap a word for its meaning and save it. Spaced-repetition practice then moves each saved word up from a rough stone, and words you practise far enough become gems. It is free on the web, or you can host it yourself. Open DigMyGem

At a glance

28 study languages in the language registry
Free plan at $0, with unlimited reading, importing, saved words and practice
Paid plans: Pro at $10 a month or $100 a year, Ultra at $30 a month or $300 a year
112 gemstones in the collection
Runs in the browser, or on your own server with one Docker Compose file
Open source under the AGPL v3 licence

Who is DigMyGem for, and who is it not for?

It is for people who want to learn one of 28 languages by reading text they choose: a news article, a novel, a PDF, subtitles or a web page. It runs in a browser, or on your own server.

How do reading and word lookup work?

You import a file or a web page and read it in the reader. These file types are accepted:

Books and documents: EPUB, MOBI, PDF, DOCX, Markdown and plain text
Subtitle files: SRT, VTT, TTML and ASS
Web pages, imported by address

How do I look up a word?

Tapping a word in the reader shows its meaning from an on-device dictionary, and you can save the word.

How does spaced repetition work?

Saved words come back in practice games: flashcards, picture to word, word to picture and listen and pick. The schedule for each word is set by FSRS, a spaced-repetition algorithm, so a word returns when you are about to forget it.

How does the gem collection work?

Every word you save starts as a rough stone, and practice moves it up an eight-level ladder. Levels 1 to 4 are stones on the way (Rough, Forming, Refining, Shimmering). A word practised to the top of the stone ladder becomes a gem, and further reviews raise its tier: Brilliant (5), Flawless (6), Divine (7) and Jewelled (8), which is jewellery. The collection page shows the gems and jewellery you have earned, from a catalogue of 112 gemstones. Gems come from practice only: a word you already knew before you used the app, or marked known, counts as mastered. It is never a gem and is not in the collection.

Flashcards: flip a card, then mark it Got it or Later. Each mark is a graded answer, like one in the other games, and flipping first counts as a hint.
Picture to word: see a picture, pick its word from four, for English words for now.
Word to picture: read a word and its sentence, pick its picture, for English words for now.
Listen and pick: hear a word, tap its picture, for English words for now.
Game Lab: describe a game and it is built for you, themed on your saved words if you like. It uses your own model key.

Each answer is graded Again, Hard, Good or Easy from what you did: a wrong answer is Again, a correct answer after a hint or a first input slower than 2 seconds is Hard, a quick correct answer is Good, and the Too easy button, pressed before you answer, is Easy. On the stone ladder an answer banks 0.25, 0.5, 1 or 2 of a level for Again, Hard, Good or Easy. A miss never lowers a level, and the word comes back later. On a gem, any answer except Again counts as one more review towards its next tier. FSRS sets the next review, with a longest interval of 180 days.

A day counts when you look up a word, answer a practice question or read. The streak counts days in a row, and the stats page draws an activity heatmap. Reading worlds change the scenery behind the app: Crystal Pines, Candlelit Reading Room and Paper Hills are open from the start; Star Road opens with a 7-day streak, Ink and Wash opens after you finish 15 lessons and Japanese Onsen opens after you finish 3 lessons.

The public Gem Wiki at /gems lists all 112 gemstones, in English and Chinese.^[2]

What does it cost?

Free, $0: unlimited reading, importing, saved words and practice, unlimited on-device dictionary lookups and free voices for reading aloud. You can bring your own AI key. Managed AI features and member voices are not included.^[1]
Pro, $10 a month or $100 a year: managed AI features with 5,000 requests a month and member voices with 300,000 characters a month.^[1]
Ultra, $30 a month or $300 a year: everything in Pro with no usage limits.^[1]
Self-hosting is free under the AGPL v3 licence: you run the same application with Docker Compose and keep your data in one SQLite file, digmygem.db. Dictionaries are separate dictionary files on their own volume.^[3]

Sources and checks

Checked on 2026-10-21. Statements about DigMyGem were written from its code; statements about other apps cite the page they were read from.

Open DigMyGem