Pick a neighbour
Tap a numbered tile, then a tile right next to it.
Free number puzzle
Make zero.
Make Null.
Combine neighbouring tiles. Up and right add, down and left subtract. Hit zero to make a Null and clear the board in the fewest moves.
Free to play
No account needed
Android · iOS · web
Try it here
Tap a tile, then a neighbour.
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Pick a tile to start.
Nulls swap with any neighbour, even diagonally.
Four rules. Countless boards.
The whole game in under a minute.
Up and right add
The tile you land on becomes the sum. The first one is spent and greyed out.
Down and left subtract
Same move, opposite direction, and you subtract instead.
Hit zero, make a Null
A zero turns into a Null. Nulls swap with any neighbour, even diagonally.
Moves work like a graph
Going up or right is positive, so the tiles add. Going down or left is negative, so they subtract. The move you make decides the sum, not the numbers.
Score the board
Make the most Nulls in the fewest moves and the shortest time. Tap Submit whenever you are done to bank your score.
Three ways to play
Compete, practise or replay a seed. Every mode plays on a Standard board with limited tiles, or an Endless board where the tile you play refills from the seed, with Classic tiles (no power-ups) or Arcade tiles (power-ups).
Head to head
Compete
Compete against other players and show your skill.
Win to earn 200 bits PLAY
5 min · 1v1
Casual
Casually play at your own pace and improve your skill. The best place to start.
Score 3+ stars to earn 140 bits PLAYCustom
Customise your board. Experiment, or create your own, and share the seed so a friend plays the exact same puzzle.
Score 4+ stars to earn bits PLAYScore, stars and XP
What the results sheet is telling you.
Every Null scores 100
Each one also earns up to 50 more for accuracy (one move per Null is perfect) and up to 50 for speed (a Null every 6 seconds or faster).
Clear the board, double it
Leave no numbered tiles and the game ends on its own with your whole score doubled. A board bonus grows the closer you get, in every mode.
Up to five stars
Stars compare your score with the best possible on that board size: 10% for one star, 20% for two, 30% for three, 45% for four and 70% for five.
Combos on Arcade boards
Nulls in a row build a combo. From the third one, each pays a growing bonus: +100, +200, +300 and on. Only a combine that doesn't make zero ends it.
Little things that keep you coming back
Everything in the app, at a glance.
Daily rewards
Open the app each day for free bits. Keep the streak going and the chest grows.
Leaderboards
Climb the global and regional ranks. Your own rank stays pinned in view, and the top three get the crown treatment.
Undo & Flip
Arcade boards are played with power-ups: take back a move, or flip a tile from + to −. Classic boards go without. Spend bits in the Store to stock up.
Stats
Track your win rate, streaks, nulls and moves across every mode, with history charts.
Cosy sounds
Soft pops for every Null and a fanfare when you win. One tap to mute.
Play anywhere
Phone, tablet or browser. Tap Play now and you are in, or sign in with Google or Apple to keep your progress.
Take a look
Straight from the app.
Questions
Quick answers before you play.
Is Num Null free?
Yes. You can play every mode for free. Bits, the in-game coins, come from playing and from the daily reward, and buy extras like Undo and Flip.
Do I need an account?
No. Tap Play now, pick a name and a country, and you are in. Sign in with Google or Apple if you want to keep your progress across devices.
What happens to spent tiles?
When you combine two tiles, the first one is spent: it turns into a blank, locked tile that can't move again. Plan your moves so you don't trap the tiles you still need.
How is my score worked out?
Every Null scores 100 points. Each one also earns up to 50 more for accuracy (one move per Null is perfect) and up to 50 for speed (a Null every 6 seconds or faster). On top of that, a board bonus grows the closer you get to clearing the whole board. Making another Null always adds to your score, and the XP you earn grows with it.
How do stars work?
Stars compare your score with the best score possible on that board size, so a 3×3 board is as hard to star as a 9×9. You need 10% of the top score for one star, 20% for two, 30% for three, 45% for four and 70% for five. In Casual, three stars or more earns you bits; in Custom it takes four.
What happens when I clear the board?
Once no numbered tiles are left, the game ends on its own and your whole score is doubled, with a special celebration on the results screen. That works in every mode, Compete included. On an Endless board the clear comes when only one number is left, since a lone number can never combine.
What is an Endless board?
A Standard board has limited tiles: play until it is clear. On an Endless board the tile you play refills with the next number from the seed, shown on a tab at the board's corner, while Nulls stay where they are. Every Null takes one number away for good, so you work the board down to a single tile and bank the double. The numbers come in a fixed order from the seed, so two players on the same seed are dealt exactly the same tiles. Casual and Custom have no clock on an Endless board; Compete keeps its five minutes.
What are combos?
On Arcade boards, Nulls in a row build a combo. From the third Null in a row, each one pays a bonus that grows as the combo goes on: +100, then +200, then +300, and so on. Sliding a number into an empty tile and using Undo or Flip keep the combo going; only a combine that doesn't make zero ends it. Undo takes back any bonus from the move it undoes. Classic boards don't pay combo bonuses.
How do Compete matches work?
You and a rival get the same board and five minutes. The better score wins the XP. If no one is online, your run is queued and matched later.
Where can I play?
On Android from Google Play (coming soon), on iOS from the App Store (coming soon), and right now in any modern browser at app.numnull.com.
Ready to make some Nulls?
Your first board is one tap away.