Default unit millimeters when opening SVG files not pixels?

[silsa]

Hello,

default unit is now millimeters when I open a SVG files. I am pretty sure it used to be pixels which makes more sense to me. Or was this information earlier saved within the file but not anymore/Illustrator not reading it?

macOS Sonoma 14.0

Illustrator 28.0

[Ton Frederiks]

There is no unit saved when you export an SVG. 

The last opened/created file or the last set unit in the Preferences is used when opening an SVG.

[silsa]

My general unit is millimeters. But it doesn't matter what the last set unit is. If I open a SVG file and change the unit to pixels, close the file and open it again, it's again in millimeters. I'm pretty the behavior is now different in AI. I've worked with lots of SVG files in past all the time but after the latest update I started noticing this unit thingy.

[Ton Frederiks]

"If I open a SVG file and change the unit to pixels, close the file and open it again, it's again in millimeters."

Do you save the SVG or do you change the unit in Preferences?

[silsa]

I figured it out. So making a new document actually changes the General unit (in Preferences). If I make a Print document it's in mm and Web is in pixels. Though now I'm a bit confused why would you have Units in the _Document_ Setup for svg files if it's actually just a unit for that session of editing, not for the _document_ itself. Changing the unit via Preferences is also a pain in the ass.

And now I actually realized my Print documents in New Document window are in Points even if the Preferences says General unit is millimeters or pixels (or anything else). Frustrating...

But many thanks for your help!

[Ton Frederiks]

Good to hear I could help.

Yes the Preferences setting is not very useful since it will change with every document you open or create that has a units setting.

Changing the unit for an open document can be easily done by right (alt) clicking in the ruler.

[silsa]

O_O Whaaaat... right clicking the ruler?! THANK YOU!

[Ton Frederiks]

Thank, it is indeed vert simple.

[hesken]

Just picking this back up in 2025 for anyone else frustrated with this. It was undoubidly the case that when saving an AI file as an SVG the width and height of that SVG would be set in pixels regardess of the units of measurement used in the document, at some point in the last couple of years that changed, the units used in the document were matched in the SVG.

This is troublesome as a lot of third party apps only recognise pixels. For example I use SVG files for a CNC router and the firmware crashes if you use anything but pixels. Until today I have typically saved the SVG, opened it in TextEdit and then manually changed the width and height of the SVG to match the pixel values used in viewBox. 

As mentioned above, a helpful and quick solution to this is to right-click on the document rulers change the units to pixels and then export the SVG. Once saved, revert the rulers back to the working units. 

However, this feels hacky, I can't help but feel there should be an option within the SVG Options dialogue to "match the document units"  if left unchecked the SVG will use pixels. 

macOS Sequoia 15.4
Illustrator 29.4

[Anubhav M]

Hello @hesken,

I understand that this functionality is important to you. Would you mind creating a UserVoice for this feature request (https://adobe.ly/3YeAf2N) and adding your comments there? Doing this will help us prioritize this request, and you will be notified of any updates.

Feel free to reach out if you have more questions or need assistance. We'd be happy to help.

Anubhav