Japan vs Bangladesh vs Palau: telling the three disc flags apart

Short answer:White field with a centred red disc is Japan. Dark green field with an off-centre red disc is Bangladesh. Light blue field with an off-centre yellow disc is Palau.

These three flags share one structure: a plain field with a single filled circle and nothing else. That makes them easy to confuse in low-resolution images, quiz questions and emoji sets. Two properties separate them completely — the colour pair, and whether the disc is centred.

Side by side

Japan

White field, red disc, exactly centred

Ratio 2:3; the disc diameter is three fifths of the flag height.
The 1999 Act on National Flag and Anthem places the disc at the true centre.
Before 1999 the regulated design was 7:10 with the disc shifted very slightly toward the hoist.

Full Japan flag page →

Bangladesh

Dark green field, red disc set toward the hoist

The disc is placed off-centre toward the hoist so that it appears centred when the flag is flying.
The field is a deep bottle green, not the white of Japan.

Full Bangladesh flag page →

Palau

Light blue field, yellow disc set toward the hoist

The colour pair alone settles it: no other national flag pairs light blue with a yellow disc.
Like Bangladesh, the disc is offset toward the hoist rather than centred.

Full Palau flag page →

How to tell them apart, in order

1.Look at the field colour first — white, dark green or light blue answers the question immediately in most images.
2.If the image is desaturated, check whether the disc sits dead centre. Only Japan centres it.
3.Check the disc colour: red for Japan and Bangladesh, yellow for Palau.

Worth knowing

Palau's disc is commonly described as representing the moon rather than the sun; Japan's disc is universally read as the sun, although the 1999 Act states no symbolism.