Mauritania vs Pakistan

Nothing about how they are built was measured the same on both.

Only Mauritania: horizontal bands. Only Pakistan: vertical bands.

Mauritania runs red, green and red from the top. Pakistan runs white and green from the pole.

Both are flown at the same shape, 1.50 : 1.

Learn to tell them apart →

Both carry a star and a crescent.

Both flags are drawn at 64×48 and cut into squares 8 across. Each square is averaged to one colour, and the score is the worst single square, so two flags that agree everywhere except one corner are as far apart as that corner, which is the right answer to a question about whether anybody could tell them apart. 0 is the same picture; the number is the worst single tile, out of 255.

On that scale Mauritania and Pakistan score 168 out of 255, which is the 66% above.

It cannot see everything. Both flags are stretched to the same box, so Indonesia and Monaco, which differ in nothing else, are measured as their reds rather than as identical. The look-alikes page sets out the rest.