Number Thread

One line through every square, numbers in order

🧵 One thread through every square — pass the numbers in order!

Logic · Ages 7+

Like every game on iplay.free, Number Thread is completely free — no ads, no sign-up, and no downloads. It runs right in your browser, so there's nothing to install and nothing to buy. With no ads and no account, it's safe to hand to a child and easy to pick up any time.

How to play Number Thread

• Goal: Draw one thread that passes through every square exactly once.
• How to play: Start on 1 and drag up, down, left or right — no diagonals. Pass the numbers in order: 1, 2, 3… Drag back along the thread to rub it out, or use the arrow keys.
• Win: Every square is covered and the thread ends on the highest number. Fewer hints, more stars!

Game modes

Pick the level that suits you — Number Thread offers 4 ways to play:

• Easy
• Medium
• Hard
• Expert

Skills you'll practise

logical reasoning, path finding, planning

Did you know?

🧵 A path that visits every square exactly once is called a Hamiltonian path — after the mathematician William Rowan Hamilton, who turned the idea into a board game, the Icosian Game, in 1856.

Frequently asked questions

Is iplay.free really free?

Yes — every game is completely free, with no ads, no sign-up, and no downloads. There's nothing to buy and no premium tier: it's free forever.

Do I need an account or sign-up?

No. Games play instantly in the browser — no login, no email, and no personal details are ever required.

Are there any ads?

None. iplay.free runs no ad networks, so there are no banners, no pop-ups, and nothing to mis-tap — which is part of why it's safe to hand to a child.

Is it safe for kids?

Yes. Because there are no ads, no chat, and no account, there's nothing inappropriate to stumble into and no personal details to hand over. You can pass a device to a child without worrying about pop-ups or accidental purchases.

Do I need to download or install anything?

No. Everything runs in your web browser — there's no app to install and no updates to manage. Just open a game and play.

What devices and browsers work?

Any modern browser — Chrome, Safari, Firefox, or Edge — on a phone, tablet, laptop, or desktop, including school Chromebooks.