A free, open-source practice app for the dMAT (digital Master Test). Enter your exam date, and it builds a day-by-day study plan, generates unlimited core-module puzzles, runs timed mock exams and tracks your weak spots. Everything runs in a single HTML file: no install, no account, no server.
Unofficial. This project is not affiliated with g.a.s.t. or the TestDaF-Institut, and the questions are not official dMAT items. Always check the latest rules and materials at d-mat.de.
New in 1.1.0: install it on your phone and use it offline, resume an interrupted session, print your plan, and a backup code that carries everything. See the changelog.
- What's inside
- Quick start
- Setting your exam date
- How to use it well
- "Explain it differently" with your own API key
- Screenshots
- Your data
- Project structure
- Contributing
- Changelog
- License
The dMAT has a Core Module (Figure Sequences, Mathematical Equations and Latin Squares, each 20 items in 25 minutes) and a Subject Module (academic texts with single-choice questions, 90 minutes). No notes are allowed. The Drill Room trains both.
| Feature | What it does |
|---|---|
| Study plan built around your date | Enter your exam date, start date and daily hours, and get a plan of 1–60 days: baseline → technique → weak areas → high difficulty → core blocks → mocks → light review. |
| Today screen | Opens on today's steps. Each step has a button that starts the right session and ticks itself off when you finish. |
| Unlimited core puzzles | Generated Figure Sequences (4×4 grids, movement, rotation, colour and x + 1 rules), Mathematical Equations (values 1–20, one unique solution) and Latin Squares (5×5, one unique answer, step-by-step solution path). |
| Adaptive difficulty | Three levels. You move up after a set at 85% or better and down after one below 60%. |
| Subject Module bank | 38 original texts with 228 questions across 8 subjects: maths, statistics, physics/engineering, chemistry/biology, economics, business, computer science, social sciences/humanities. Six question types: calculation, table/chart reading, concept check, I/II/III statements, EXCEPT, and transfer scenarios. |
| Exam and Learn modes | Review at the end, or see the answer plus the trick behind it after every question. |
| Mock exams | Two full mocks (3 × 25 min core → 30 min break → subject set), plus unlimited core-only mocks. |
| Mistake bank | Every wrong answer comes back a day later. It leaves the bank after two correct answers in a row. |
| Pacing feedback | A seconds-per-item chart plus warnings for rushing, overthinking and running out of time. Timed sets show a live "on pace" badge. |
| Trick cards | 59 recall cards with spaced repetition (1 → 3 → 7 → 14 days). |
| Exam-day mode | Hides hints, labels and feedback until the end, just like the real test. |
| Keyboard shortcuts | A–E Latin squares · 1–4/A–D subject · 1–6 figures · ←/→ move · F flag · Enter check / next. |
| "Explain it differently" | Optional. Add your own API key (Anthropic or any OpenAI-compatible endpoint, including a local model) and every explanation gets a button that asks for a second explanation in different words. |
| Four themes | Clean (follows system light/dark), Warm, Forest and Night. |
| Works on phones | Responsive layout and large tap targets. Install it from the browser menu ("Add to Home Screen") to get an app icon and full offline use. |
Option 1: just open it
- Download the ZIP, or clone the repo:
git clone https://github.com/PaddyCH96/dmat-drill-room.git
- Double-click
index.html. It opens in your browser and works offline, apart from the web fonts, which fall back to system fonts.
Option 2: use the hosted version
If the repo owner has enabled GitHub Pages, open https://paddych96.github.io/dmat-drill-room/.
Install it on a phone
Open the hosted version in Chrome or Safari and choose "Add to Home Screen". After the first visit it works offline — useful on a commute, and it keeps the browser's tabs and notifications out of your practice.
Option 3: host your own copy
Fork the repo → Settings → Pages → Deploy from a branch → main / (root) → Save. Your copy will be live at https://<your-username>.github.io/dmat-drill-room/ in a minute or two.
The first time you open the app, it asks for:
| Field | Used for |
|---|---|
| Exam date and start time | The countdown and the exam-day screen |
| Start the plan on | Day 1 of your plan (defaults to today) |
| Study hours per day (1–8) | Spacing the day's steps. Days under 4 hours get fewer repeat sets. |
| Daily study starts at | The times shown on each step |
You can change any of these later in ⚙ Settings. Your scores, mistake bank and cards are kept. Plans shorter than 9 days keep the most valuable days (baseline, Figure Sequences, Mock 1, light review), and longer plans add extra weak-area, high-difficulty and core-mock days. The longest plan is 60 days.
- Day 1: read the official preparation materials and videos, then do the diagnostic sets. Your first results set your level and start filling the mistake bank.
- Every day: start with 5 minutes of Trick cards, follow the Today screen, and finish with Redo mistakes.
- Never take notes, not even in practice. The real exam doesn't allow them.
- Guess rather than skip. An unanswered item is always wrong.
- Weight your subject practice toward fields outside your own background. You can't choose topics in the General Academic Module.
- Take the mocks in exam-day mode in one sitting, ideally at the same time of day as your real test.
| Subject Module (Learn mode) | Figure Sequences drill |
|---|---|
 |
 |
| Results with pacing | Progress |
|---|---|
 |
 |
| Night theme | Mobile |
|---|---|
 |
 |
Every explanation in the app can carry a button that asks a language model for a different explanation: another mental method, a memory hook and a common trap. It is entirely optional — the app is complete without it.
Set it up: ⚙ Settings → "Explain it differently" → pick a provider, paste your key, Save, then Test it.
| Provider | Key | Model | Base URL |
|---|---|---|---|
| Anthropic (Claude) | sk-ant-… from console.anthropic.com |
e.g. claude-sonnet-4-5 |
default https://api.anthropic.com |
| OpenAI-compatible | your provider's key | e.g. gpt-4o-mini |
https://api.openai.com/v1, or your own, e.g. http://localhost:11434/v1 for Ollama |
Any endpoint that speaks the /chat/completions API works, so you can point it at Groq, Together, LM Studio, Ollama or your own gateway. For a local model the key can be any non-empty string.
Where the key lives. In your browser's local storage, on your machine, and nowhere else:
- it is excluded from the backup code and from account sync, so it cannot travel to another device by accident;
- it is sent only to the provider you chose, directly from your browser;
- there is no server in this project and no telemetry — check
src/ai.js, it is about 90 lines; - anyone who can use your browser profile can read it, so use a key with a spending limit and press Remove key when you are done;
- each explanation is one short request (500 tokens max), so costs are small, but they are yours.
Cloning the repo does not commit any key: there is no .env and nothing to fill in before building. If you fork this and add a hosted backend, do not put a key in the client.
A note on browsers: Anthropic's API needs the anthropic-dangerous-direct-browser-access header for browser calls, which the app sends. Some OpenAI-compatible providers block browser origins with CORS; if Test it reports that the provider could not be reached, that is usually why, and a local endpoint or a provider that allows browser calls will work.
- Progress is saved in your browser's
localStorage. Nothing is sent anywhere, except the explanation requests you trigger yourself (see above). - To move to another browser or device, use ⚙ Settings → Copy backup code, then Import code on the other device.
- Reset all progress in Settings clears scores, mistakes and cards. It keeps your exam setup.
- Optional: if you publish
index.htmlas a Claude artifact with thedb,userandsamplecapabilities, progress syncs to your Claude account and every explanation gets an "Explain it differently" button. Outside Claude, these features simply stay hidden.
dmat-drill-room/
├── index.html ← the built app (open this)
├── sw.js ← service worker (generated; offline support)
├── manifest.webmanifest ← makes it installable on phones
├── icons/ ← app icons
├── build.mjs ← bundles src/ into index.html and sw.js
├── tests/check.mjs ← checks the question bank, generators and planner
├── src/
│ ├── styles.html ← CSS and themes
│ ├── layout.html ← page shell (header, tabs, footer)
│ ├── generators.js ← Figure Sequences, Equations, Latin Squares
│ ├── questions-1/2/3.js ← Subject Module texts and questions
│ ├── subjects-and-tricks.js ← subject areas, question types, trick cards
│ ├── plan.js ← setup screen and study-plan builder
│ ├── app.js ← sessions, practice, mocks, progress, sync
│ ├── ai.js ← optional "Explain it differently" providers
│ └── features.js ← Today screen, mistake bank, pacing, shortcuts
└── docs/screenshots/
ARCHITECTURE.md explains how the pieces fit together: state, the session engine, the plan builder and where to add things. Each file in src/ starts with a short header saying what it holds.
To make changes, you need Node.js 18 or newer. There are no packages to install.
node build.mjs # rebuild index.html and sw.js after editing src/
node tests/check.mjs # run the checks (also run on every push by GitHub Actions)The checks cover the question bank's shape, that every generated Latin square has exactly one possible answer, that figure options are distinct and never overlap, that the planner produces valid days and times for every length from 1 to 60 days, and that the backup code survives a round trip. CI also fails if index.html or sw.js differs from a fresh build.
New subject texts, trick cards and bug fixes are very welcome. See CONTRIBUTING.md for the question format and workflow, and ARCHITECTURE.md for how the code is organised. Please only submit original material: don't copy official dMAT or TestAS items.
If this helped you prepare, a ⭐ helps other candidates find it.
MIT © 2026 PaddyCH96