SU 2018 : 2019 compatibility?


Just a quick question before activate my upgrade to 2019;
Are the two file versions interchangeable?
I.E. can 2018 import a file created by 2019?.. or will I have to ‘downsave’ my files, creating 2 different versions - and if I do that, , does downsaving lose any information from the model?



An older version (2018) cannot open file formats that it does not know (2019 .skp format). So they are unfortunately after so many years still not interchangeable.
You can either

  • downsave a copy in skp 2018 format
  • or only save your project in 2018 format
  • or install the extension Legacy Save and set SketchUp 2019 to save by default to and older version
  • or build the extension Open Newer Version with the 2019 SDK and install it in SketchUp 2018 so it can open newer 2019 files.

Since skp is not an extensible file format (of which older program versions would just ignore the features they don’t know), I guess downsaving would lose new features like line styles.


That’s right the new line styles are lost when you downsave from 2019 and open in 2018, the layer is preserved though. (just tried it)


Thanks for the reply.

So I decided to install 2019 and test it.

  • saving to 2018 format will remove linestyles, even when imported straight back into 2019. (so if anybody within your pipeline is still on 2018, you can’t rely on linestyles)

  • Line styles will save when exporting to DWG (however the linetype scale is interpreted very differently)

  • Linetypes will not import back from DWG (nor will dimensions or text).


There has always been “backward” compatibility in that later versions can read and write earlier versions but not vice verse. 2019 added dashes to layers, so that will be lost if you down save to 2018 but I can’t recall anything else.


SketchUp is always backwards compatible, but never forwards compatible. Specifically, SU2019 can open and save models in SU2018 format, but SU2018 can neither open nor save models in SU2019 format.