Belt Tips: Sorting Faster Than the Conveyor

Updated October 2026

Belt is a sorting race that gets harder in two separate ways. The rate at which boxes appear rises over the first minute and then holds steady, while the belt itself keeps getting faster with every point you score. Knowing which of those two pressures you are fighting at any moment, and a few precise facts about where a box can be grabbed and dropped, is what separates a short run from a long one.

The layout and the basic rules

The conveyor runs across the lower part of the playing area and carries boxes from left to right. Three bins sit across the top, always in the same order: red on the left, green in the middle and blue on the right. Each box is one of those three colours, chosen at random, so there is no pattern to memorise.

You start with three lives and they never come back. A box dropped into the bin of its own colour scores one point. A box dropped into the wrong bin costs a life, and so does a box that rides off the right end of the belt. The run ends when the third life is gone. The belt stands still until you start: when you open the page it waits for your first touch, and after Start or New it starts at once. The first box arrives about 0.6 seconds later.

The two clocks: spawn rate and belt speed

New boxes arrive at intervals that depend on how long the run has lasted. At the start the gap is about 1.6 seconds. It shortens steadily over the first 50 seconds of play until it reaches 0.7 seconds, and then it stops changing. Each gap also varies at random by up to 0.15 seconds either way. After that first minute you face, on average, a new box roughly every 0.7 seconds, or about 85 per minute, for the rest of the run.

The belt speed works differently. The playing field is a fixed area 360 units wide and 560 tall that is scaled to fit your screen, and the belt speed is measured in those units. It starts at 70 units per second and rises by 1.2 for every point you score, with no upper limit. At a score of 50 it is 130, at 100 it is 190 and at 200 it is 310 units per second. The speed changes the moment you score, and it applies to every box already on the belt.

A box needs to cover 426 units between appearing at the left end and counting as escaped. That gives each box about six seconds at the start, a little over three seconds at 50 points, about 2.2 seconds at 100 points and about 1.4 seconds at 200 points, on every screen size. Because the speed keeps rising, every run eventually ends: in our simulation a sorter that reacts in 0.3 seconds and takes half a second per box was overrun at about 1,000 points, after roughly twelve minutes, and even a superhuman one at twice that speed lasted about 25 minutes. The arrival rate stays the same, so as the belt speeds up there are fewer boxes on it at once, but each one gives you less time.

Exact grab and drop rules

A touch picks up a box if it lands within 44 units of the box centre, both sideways and up or down. That is a square twice as wide as the box itself, and when two boxes are inside it the closer one is taken. You do not need to hit a box precisely; aiming at the belt just in front of a box works.

While you hold a box it stops moving entirely. It keeps the same offset from your finger that it had when you grabbed it, so if you take it by its lower edge, the box sits slightly above your fingertip. What counts on release is the position of the box centre: it must be horizontally within the bin, and vertically anywhere from 10 units above the top of the bin to 10 units below its bottom. The three bins share the width almost equally, with 16-unit margins at the sides and 16-unit gaps between them.

If you let go anywhere else, nothing bad happens. The box goes back onto the belt at the spot where you picked it up and carries on from there. That includes the gaps between bins, so a release that misses every bin is always safe, while a release that lands over the wrong bin is not.

Holding boxes and last-moment saves

You cannot rewind a box. A box released away from the bins returns to the place you grabbed it, so dragging it back to the far left gains nothing. What you can do is hold it: a box in your hand does not move, so when two boxes reach the end together, grabbing the more urgent one stops its clock while you decide. The cost is that your hand is busy and every other box keeps travelling, so a hold only helps for a moment.

The escape check is also slightly generous. A box counts as lost only once its centre is a full box width beyond the right edge. For a brief moment after it has slid out of view, a touch at the very right end of the belt can still catch it. At low speeds that window is about a third of a second; at high speeds it is a small fraction of that, so treat it as an emergency save rather than a plan.

Choosing which box to sort

Because only escapes and wrong bins cost lives, the box nearest the right end is almost always the one to move first. Work from right to left. If the next box is far enough back, sort the rightmost one; if two boxes are both near the end, sort the one closer to escaping first and go straight back for the other.

Learn the bin positions so that your hand moves without looking up. Red boxes go to the upper left, green straight up, blue to the upper right. Short, direct strokes are faster than curved ones, and a stroke that ends a little high inside the bin is safe, since the drop zone extends slightly above and below each bin.

Accuracy matters more as the run goes on. A wrong bin costs a life that will never come back, while a missed drop over a gap only costs time. When unsure, release short of the bins and try again.

Screen size and timing

Screen size does not change the timing. The whole field is drawn at a fixed shape and scaled to your screen, so a box gets the same time at the same score on a narrow phone, a wide phone or a tablet, and turning the device simply redraws the same field larger or smaller. On a very small screen the boxes and bins are drawn smaller, which makes aiming a little harder, but the timing is identical.

The game pauses when you switch to another app or tab, since it runs on the animation loop.

A practice plan

1. Play a few runs using only right-to-left order to build the habit of serving the nearest box first.
2. Practise the hold: when two boxes are close to the end, grab the more urgent one, then sort it and go straight back for the other.
3. Practise direct strokes into each bin until you stop looking up at them.
4. Set a target of 100 points, where the belt has nearly tripled its starting speed, and then push beyond it.

Your best score is kept on your device, and any score above zero can be saved to the Hall of Fame from the game-over card.