Breathing Square Optical Illusion


This one actually is really good (as simple as it may appear)! Observe the animation on your right: behind a grid of yellow boxes there is a purple rotating square. As the square rotates, we only see the part of it not covered by the grid. It appears to grow and shrink in its roatation, as if it were breathing! Am I right?

In reality none if this is true – the square remains same in size at all times. It’s just that our brain perceives it “breathing” and changing size. Would be cool if someone could make a solution .gif file, without the yellow grid and attach it through comments… anyone? Hope you like these simple, old-school illusions the same way you like real-life ones?

  • z2d4th

    Ya, on my first glance i did not noticed the square box.

  • Andrew

    I became curious and redone both the original and the explanation. It’s a little rough with a smaller number of frames.

  • SK

    Well, are you sure it’s an illusion?… even if the square’s size remains the same, the size of its visible surface really change. So it shrink of course…

  • hockeyplayah

    Are you sure that square is purple? It looks blue to me.

    • michy

      u r looking at ur computer at the wrong angle.

  • gissehel

    Ok, so no .gif here, but a html5 web page featuring the original illusion and the same with 30% opacity on yellow squares, all using html5 transitions.

    Modern browser required.

    • Kelsey

      That html5 example just shows what a mess the html5 “standard” is. You have to have 5 separate blocks of code; the “standard”, one for IE, one for Opera, one for Safari/Chrome and one for Firefox.

  • Jarmo

    Much like the perspective illusions are the lamest, this kind of illusions are the awesomest. Brain explodes.

  • bandit885

    I can’t read the 1st paragrapg because of the “won’t back down” ad at the top of the page. the close X does not work.

  • bandit885

    well, now that I submit, it’s gone.

  • Adele


    It’s a simple but effective illusion. Since you asked for a solution gif, I went ahead and made a really quick one. Hope this helps show that the blue square is just rotating and not changing size! ^_^

  • AmetuerAspirant

    well this is something i’ve never seen before, incidently, do you have any of those illusions where you drag a striped piece of paper over an image and make it look like it’s animated?

  • Lance

    Ask, and you shall receive.


  • clues

    That’s very cool! Love it. <3

  • clues

    That’s very cool! Love it.

  • Josue Boo

    This can’t be! I think the rotating square is “breathing”.

  • Michael

    I actually doubted that the effect was real, and so decided to check if it was a trick. I took an image using the Print Screen function when the corners of the square were in the cross, pasted the image into paint, measured the hypotenuse of the square with a real ruler on my screen, and calculated what the side length would be. I then took a second image when the sides of the square were vertical, and measured the length from one side to the other. Boy do I feel stupid; the square isn’t changing size after all. I also would like to apologize for doubting you Vurdlak. Sorry that I did not trust your judgement.

  • Mary

    This one worked for me on the thumbnail, when it wasn’t animated, I could see a circle of blue behind the yellow squares.

  • Joseph


    I stared at it a while before reading the post and couldn’t see any illusion. Then I read your post and was absolutely floored by what the illusion was.

    A really powerful illusion.

  • Asel


  • CarnivioN


  • Max


  • here’s a near-copy of that “purple” rotating square without the grid


  • i even tried remaking it and here’s how it looks


  • Tom

    For a split second it even looks round to me.

    • AB

      Tom and John, I didn’t notice the split second circular look until I read your posts but I do see it.
      Cool illusion!

  • Matjl

    Thats really cool, with a really strong effect

  • John

    Did you notice that when the blue square is not moving (and is in the same horizontal plane as the other 4 squares) sometimes when you are looking at one of the brown squares the blue square can appear to be a circular.

  • Phaeton99


    Proof of the constant size.

  • jc daddo

    Is this what you were after[img][/img]

  • i cant see the photo response i posted…

  • trythis

    What is all the fascination and wonderment with is? If you were viewing the silhouette image of May West through only a very narrow horizontal slit opening in a piece of paper and moving it up and down, would you be saying that what you can see though the slit is a magical illusion? Hmmm. Hey, I take this all back. Substitute whomever voluptuous bombshell you can think of and analyze this to death. Looking forward with whatever the greatest minds can conjure up. I love science.

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