← APPSTHRUM
DEEN

LinkthrumFree online line puzzle

Connect matching colored dots and fill the whole board. Try 100 logic puzzles: 50 flat boards and 50 cube levels. Free in your browser, with no ads and no account.

Free in your browser Play now Download on the App Store

Also available as an offline iPhone and iPad app on the App Store.

100% free. No ads. No account.

All 100 levels are free to play. No subscriptions, in-app purchases or trackers. Your solved levels and best move counts stay on your device.

What's in the game

100 levels, flat and on cubes

50 flat boards from 5 × 5 to 9 × 9 and 50 cube puzzles. On a cube, guide lines across the edges of three visible faces. Every level can be solved with the whole board filled.

Hunt the perfect star

Solving is one thing — solving without a single wasted move is another. Every level tracks your best score and rewards a flawless run with a star.

Glowing pipes, real feel

Draw glowing lines with your finger or mouse. Shorten paths and redraw them as you solve the board. Browser sound starts off; optional haptics are available on supported devices.

Private & open source

No trackers, analytics, cloud or account. Your progress stays on your device. Open source, in English and German.

More free apps

Linkthrum is part of Appsthrum — a growing collection of apps from the dyslexia community. All of them free, with no ads and no tracking.

See all apps by Mario Engel →

How to play Linkthrum

  1. Connect the colors

    Choose a level and drag from a colored dot to its matching partner. Use your finger or mouse.

  2. Fill every cell

    Connect every pair without crossing paths or leaving empty cells. In cube levels, the paths continue across the edges of three visible faces.

  3. Try for a perfect star

    Complete each connection in one move to earn a perfect star. Replay any level to improve your best move count.

Questions about the game

Is Linkthrum really free?
Yes. All 100 levels are free, with no ads, subscriptions or in-app purchases. You do not need an account.
What kind of puzzle is Linkthrum?
Linkthrum is a line and logic puzzle based on the Numberlink principle. You connect matching colored dots instead of numbers. Paths cannot cross, and you must fill the entire board.
How many levels are there?
There are 100 levels: 50 flat boards from 5 × 5 to 9 × 9 and 50 cube puzzles. On cubes, guide the lines over three visible faces.
Can I play without a download?
Yes. Open the browser version on your phone, tablet or computer. Play with your finger or mouse. No app installation is needed.
Does Linkthrum work offline?
The installed iPhone and iPad app works offline. Open the browser version online first and let the files load. You can then play offline while your browser keeps those files.
Where is my progress saved?
Solved levels and best move counts stay on your device. There is no cloud sync. Clearing browser storage also removes the game progress saved there.

Play now

Legal notice

Publisher Dyslexia Research Center USA

Responsible for content Mario Engel · marioengel@me.com

App Linkthrum for iOS and the browser · free, open source, no data collection

Contact

Questions, praise, bug reports? Write me — I read every message.

Mario Engel
marioengel@me.com

Privacy

The game has no advertising, tracking or account. Solved levels and best move counts stay on your device. The iPhone and iPad app works offline. The browser game loads its files from this website and can then use its offline cache. This website uses no analytics or tracking cookies.