What counts as a difference
Every production pair has exactly five intentional changes, and each is one of these: something added or taken away, something moved, a changed shape, a different number of things, or a new pattern. A change never depends only on telling two similar colours apart.
Choosing a difference
Tap or click the change in either picture. Both pictures get a ring and the trail at the top fills in: “3 of 5 found”. Tapping a found difference again does nothing harmful. A wrong tap shows a small grey circle and costs nothing.
Looking closer
Use Zoom in, Zoom out and Fit below the pictures, scroll with a mouse wheel, or pinch on a touch screen. Both pictures always zoom and move together. Once zoomed in, drag to move around; dragging never chooses anything.
Keyboard
| ← → ↑ ↓ | Move the crosshair (hold Shift for small steps) |
| Enter | Choose the spot under the crosshair |
| + − 0 | Zoom in, zoom out, fit |
| H | Hint |
| Esc | Pause menu |
Hints and text clues
A hint draws a dotted circle around one difference you haven’t found. Text clues describe, in words, the area to look at. Both are optional and mark the pair as assisted on your result. Clues help you look; they don’t replace the pictures, and Hidden Trail is not a non-visual game.
The daily pair and streaks
The daily pair changes at midnight UTC and is the same for everyone. Find all five on its day to add a day to your streak. If you started before midnight you get two extra hours to finish. Pairs from the archive never change your streak, and finishing the same day twice still counts once.
Time
The clock only shows how long you spent looking. It pauses when the menu is open or the tab is hidden, and it never affects anything.
Settings
Open Settings (the slider icon at the top) for light or dark mode, sound, reduced motion and larger controls. Larger controls also make the tap area around each difference a little more forgiving.