@ Rein:
Until an actual fix is available, the only way I am able to keep the artboard and the art in register is to first select one corner of the artboard as the reference point (origin) and scale the artboard first, using the numbers. As long as Constrain width and height proportions is on, you can type a percentage in H or W for precise and repeatable scaling.
Then, for the art, use the Scale tool and select the same corner of the artboard as the reference point of the art and then scale the art to match with the same percentage.

I have same problem. I got graphics in 1920x1080 and I need to animate it in After Effects, but I decided to animate in 3840x2160. So how can I resize artboard with graphics so that all relations stay same.

Can you implement something that parallels the Photoshop Image > Image Size?

@ Neeraj: 3, 4, 1, 2

Please, please, please do this! It would make our lives sooo much easier!

I can't believe this hasn't been answered yet. I, too, need an easy solution to this. I can't imagine that we're the only ones who need to resize already completed artboards AND the art inside them!

the below link does not cover the subject.
I appreciate the poster reaching out to try to share knowledge.

Resize Art board and ART at the same time.

https://www.youtube.com/watch?v=NoPungS8KXI

Yes, you can change all ARTBOARD size at once, watch here:

https://www.youtube.com/watch?v=NoPungS8KXI

urgently needs a fix!

3, 2, 4, 1 this needs a fix

In order of importance, I'd say: 3, 4, 1, 2

Hi Neeraj;
3) is most important, followed closely by 4) .
1) less so - perhaps it should be a preferences option?
2) seems niche to me. Nice to have, if you happen to be switching tons of artboards between known sizes. But this is by no means the general use scenario which absolutely 3) is.

Typing in an adjustment to width or height secondarily click and drag to resize and would be my preferred methods.

Thanks Neeraj, but I'm not technical, so I apologise missing what you're saying.

As voted for in this thread, to be able to transform both artboard and objects synchronously and simultaneously has been a fundamental function lacking for years.

Just think of all the layers in PS. You have to resize all the layers one by one?

That's what's happening in AI sir.

Thanks for raising this request.

We'd like to hear your opinion on what all should be considered as a part of this feature.

There are four different ways of transforming an artboard in editing mode:
1. Horizontal to Vertical (and vice-versa) orientation change
2. Picking a different preset from dropdown (e.g. Letter to A4)
3. Cursor based scaling from the eight controls of selected artboard, and
4. Changing numbers in the W/H fields in panels

Which of these do you think should be considered as a part of this feature? Please share your thoughts in the comments.

Can you please make realistic, not true view? Thank you.

I could REALLY use this feature. A lot of my logos I design depend on the artboard size for the logo lockup to send to clients so they know how much cushion to give the logo when designing something. It's a pain in the butt to resize both manually.

Agree - need it almost daily! Adobe please implement ASAP

Still no action for this? I'm in the same position as the OP. This issue can't be something that is not common. I mean, to have numerous artboards and not be able to mass edit is not okay. I hope this is resolved soon.

Really so much time passed. When someone start to implement it? Looks like never. 1 year passed since I've created this. lol. or not? Well it's very soon, this 4 month will pass very quickly.

Thats really AWKWARD. Such a simple and useful thing and voted - and been ignored..