Adobe Illustrator - How to remove unwated pixel after export?

If the upper left corner X Y coordinates and the W H values don't contain fractions, it should not give "transparent" pixels.

But there is another reason to get these additional pixels.

When you export to a resolution other than 72 ppi or multiples like 144, 288 ppi, you should not get those "transparent" extra pixels.

150 and 300 ppi are likely to give you these extra pixels due to rounding to whole pixel values.

All four edges of the square have to line up exactly with the pixel grid referenced in the document's settings. If the edges are off at all in size or position you'll get the fuzzy edges when exporting. If all you need is a solid colored pixel-based box it's much easier to create a new document in Photoshop to the exact pixel size of the box needed, choose the desired color, fill the background and then save it as a PNG image. JPEG may introduce subtle compression noise into the image, yielding the same kind of non-solid coloration you're seeing in the object edges.

Benydc,

Are the corners/sides of both the rectangle and the Artboard at whole X and Y pixel values?