75 votes65 comments · Illustrator (Desktop) Feature Requests » File Save, Import and Export · Flag idea as inappropriate… · Admin →Under Review · AdminNitish Agarwal (Illustrator on Web/iPad Team) (Lead Software Engineer, Adobe Illustrator) responded
If you will export artboards in any fractional scale or by specifying height and width you will get correct output.
The best way to not get an extra pixel is keep your artboard coordinates in integers. You can achieve that by changing the reference point of artboard to top left and typing in the nearest integer or do Make Pixel Perfect(Object > Make Pixel Perfect). If size of your artboard is increased please manage that accordingly and export.
Thanks & Regards
An error occurred while saving the commentAlyssa commented
I'm having the same issue! I've created a load of web ads for my company and most of the 72dpi exports have 1 extra pixel and the uploads are getting rejected. Some of them it's just 1 pixel others are 2 pixels (1 extra length and 1 extra width) and others exported correctly. Completely maddening! And exporting each individually with "save for web" would have taken longer than fixing the exports in Photoshop.