Two things are worth knowing about SketchUp Model before you try to open one. A .skb file is the Windows auto-save backup of the same model — rename it to .skp to recover a crashed session.
| Signature | SketchUp Model (UTF-16LE version string near the start) at offset 0 |
| Written by | Trimble Inc. (originally @Last Software) |
| Usual MIME type | application/vnd.sketchup.skp |
| Full name | SketchUp Model |
What is actually stored
Little-endian binary with a UTF-16LE version string at the head of the file; geometry, components, materials, tags and saved scenes follow.
The version string decides everything: a newer SketchUp opens older files, an older SketchUp refuses newer ones, and Save As can write down to an older version.
How we identify it
The format announces itself in plain text: SketchUp Model (UTF-16LE version string near the start) near the start of the file. If that string is missing, whatever produced the file is not what the extension claims.
Someone sent us a .skp file with a .tmp suffix on it last month; the header was the original all along and only the name had been changed. Renaming does not rewrite a header.
Opening it without the program that made it
Installed options: SketchUp Pro / Make, SketchUp Viewer (free, read-only), Blender (import), Microsoft 3D Viewer (exported GLB only). None of them have to be the program that made the file: Universal Viewer reads it and writes nothing back.
Getting it out of .skp
The targets people actually ask for are .stl, .obj, .dae, .fbx, .dwg. Each one has its own page with the settings that matter: skp → stl, skp → obj, skp → dae, skp → fbx, skp → dwg
Asked often
What opens .skp if I do not have Trimble?
SketchUp Pro / Make, SketchUp Viewer (free, read-only), Blender (import). If nothing installed reads it, the viewer above does.
Can I convert .skp without the original program?
For the targets listed above, yes. The container survives; what is lost is whatever the target format cannot hold.
How do I know a .skp file is real?
The format announces itself in plain text: SketchUp Model (UTF-16LE version string near the start) near the start of the file. If that string is missing, whatever produced the file is not what the extension claims.
Last looked over 2026-10-05 by M. Halvorsen.
Notes from the file library
Files of this kind are catalogued with the family named in the table above. The family groups them by what a file carries, not by the application that wrote it, which is why two extensions from the same application can sit in different families.
Two things decide whether a file can be opened on a machine that never had the application that made it: the header, which says what the container is, and the structure behind it, which says whether the contents can be read at all. The conversion guides listed on the page cover the targets that come up most often.
Format pages are rebuilt with each release of the toolset, and the review line at the bottom of the page is when an editor last checked the entry against a file. If a page disagrees with a file you have, send the first sixteen bytes and the build number to the support address and the entry is corrected in the next build.