About Spot the Difference

Two pictures of the same scene sit side by side — a garden, a seaside, a street at night, a kitchen — and they are not quite the same. A roof has been painted another colour, a bird faces the other way, a flower is missing, a window has its light on. Tap a difference in either picture and it is circled in both. Find them all to finish.

Every scene is drawn fresh from a seed rather than taken from a stock of photographs, so there is always another one, and the differences are chosen from what each thing in the scene could plausibly lose or change. None of them hides behind anything else, no two sit close enough for one tap to be ambiguous, and every one has been checked to change what you can actually see — the pictures are compared pixel by pixel when each scene is made, and nothing differs outside the marked places.

The clock runs from the moment the pictures appear. A tap that finds nothing adds five seconds, so guessing is expensive, and a hint shows you where to look for twenty. Easy scenes have five bold differences; medium has seven; hard has ten, some of them as small as a star in the night sky or the number of petals on one flower. The daily challenge gives everyone the same medium scene and ranks the day by time.

Tips to win

• Work across the pictures in strips — the sky, then the middle, then the ground — rather than darting about
• Look at one thing at a time in both pictures: the house, then each tree, then each flower
• Colours are the easiest to see at a glance; things facing the other way are the easiest to miss
• Count things that come in groups — windows lit, stars, shells, petals