@Ruud, these sizes do indeed result in nice round pixel results.
It is easy to calculate if your artboard size will generate extra pixels.
Just divide the lenght of a side by 72 and multiply by the export resolution.
If the result is a round value, no additional pixels will be generated.
Your example: 2880÷72=40. 40x300=12000 pix
2160÷72= 30. 30x300=9000 pix
Will result in nice round values.
But 2800 x 2200 would give:
2800÷72=38,88888889. 38,88888889x300=11666,66666667.
2200÷72=30,55555556. 30,55555556x300=9166,66666667.
The fractional results will give additional pixels.
Resolutions that are multiples of 72 ppi will result in nice round values.
2800÷72=38,88888889. 38,88888889x288=11200.
2200÷72=30,55555556. 30,55555556x288=8800.

What may help a lot is choosing a nice art board size.

In my case 2880 x 2160 px, which results in an exported png of 12,000 x 9,000 px. Or 40 x 30 inch @ 300 dpi.

This issue now never occurs anymore.

I'm guessing that its because Illustrator isn't just for digital i.e. pixel based media, its also still used for print, and arbitrary metric or imperial measurements which don't follow exact pixels. The solution would be for Adobe to update templates for web and other digital formats where certain preferences like snap to pixel are enabled for elements and artboards alike.

I'm now used to making sure the documents are digitally prepared before I export assets. But it still catches me out.

Seeing some discussion on this today, just want to say I saw this as an issue nearly ten years ago. Since then I've... left my first job, gone to school again, worked in another industry, switched to Sketch, switched to Figma, come back to the first company, started using Illustrator for a few things again and....

This still isn't fixed.

Well I agree, this is an annoying bug, and Adobe should look at this issue, I have no idea if the problem is fixable, you'd thought that artboards could only be moved and created already snapped to a pixel.

The only workaround at present is that all artboards including those which overlap other artboards must have their x and y values set to whole pixels. Which is theoretically correct unless you have an artboard placed behind another object whose positions are not in whole pixels - then there is no workaround.
If however all assets and artboards are in whole pixel dimensions, then placing their x and y values should align.

Where individual objects are concerned, you can turn on snap to pixel, but the object must first be either drawn after switching the snap on, or manually move it align to whole pixels.

Ok but what do you do when there are multiple artboards with sizes that overlap the x and y coordinates? Is this a bug that is unfixable? It shouldn't matter where my artboard is for exporting/

The issue effects both the artboard export itself - AND any asset selected for export either on or off the artboard. The xy coordinates values of the selected object must also be rounded to whole pixels in order to output at the correct pixel dimensions.

Jason, the same is also true for objects outside the artboard. If the object upper left X/Y position contains fractional pixels it will add additional pixels.

The artboard has nothing to do with it. This is a separate asset all together that I exported outside of the artboard. The only fix around is to “Save for Web” but this slows down my workflow dramatically.

Jason, please check the coordinates of your artboards. Currently these need to be integer to avoid the 1 extra pixel. If it’s not the case — please share more details about the layout.
I’m merging your report with the larger one.

This has been an issue for many years and it has not been fixed. I export a file and it always adds an extra 1px

It's crazy to me that this issue remains unresolved.

If a user sets an artboard size, the exported artboard should match that size. No finnicking around should be necessary. As stated by an admin YEARS ago, "Ai knows the size of artboards to be exported and yet it does not deliver the set sizes"

Instead of addressing a fundamental issue like this, seems like most effort is put towards unwanted and unwelcome A.I. features

Even artbords that were perfectly aligned will land on fractional pixel coordinates with the new 29.6 rearrange behaviour.

The new rearrange artboards feature in 29.6 causes all artboards to be off the pixelgrid.
You need to click to define the position and that it always off.
In previous versions using rearrange artboards would fix artboards that were not aligned.
Try this file in an older version and in the 29.6 version.

It's mid-2025, but I'm having the same issue from 2017. Hmm...

Can be merged, thank you. I hope the problem can be resolved as soon as possible

Yep, you tested it properly and came to the right conclusions.
To have the results pixel perfect, the artboards (in pixels) should have integer values, integer coordinates (from the corner, not the center), and the resolution should be a multiple of 72 ppi, which is 1:1 on PostScript, where pixel equals point.
When these are not honored exactly, rounding happens.

The larger problem you commented on recently (http://illustrator.uservoice.com/forums/601447/suggestions/30992416) is specifically about trimming the extra 1 px row and column of the resulting images to match the desired size EVEN when the COORDINATES only are not integer, but SIZES are — as set by the user.

It seems pretty similar, so I think it can be merged, if you wish to.

Encountered the same problem
https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/49294934-exporting-to-multiple-screen-formats-results-in-pi

After testing, the method to remove white edges is as follows:
1. By setting it as pixel level optimization
2.Select "1x, 2x, 3x..." in "Format Scaling" to remove white borders. If the resolution selected for "Format Scaling" is not a multiple of 72, such as 100pi, 150ppi, 300ppi, white borders will appear after export.

If set to pixel level optimization, the size will change when exported in units such as millimeters, centimeters, meters, etc.
I hope this issue can be corrected.

The 'png, jpg, webp' files exported using the 'export to multiple screen formats' method show a 1-pixel offset.