What a .skb file is
When you save a model, SketchUp for Windows first keeps the previous version of the file next to
it, with the same name and the extension .skb (SketchUp for Mac adds a ~ after .skp
instead). It is a complete SketchUp model, one save older than the .skp. When the .skp won't
open after a crash, the .skb is usually the best copy you have.
Opening it
The usual advice is to rename Model.skb to Model.skp and open it in SketchUp. That works
when the backup is whole and your SketchUp is at least as new as the one that saved it. This
page also covers the cases where it doesn't:
- The backup won't open either. It may have been caught by the same crash, or synced half-written. Upload it as it is: what is readable is recovered, and the result page says what was lost.
- You have both files. Upload the
.skpand the.skbtogether. Each is checked, the one holding the most of the model is used, and texture pictures missing from it are taken from the other. - Your SketchUp is older than the file. The model is written as a SketchUp 2017 file, which SketchUp Make 2017 and every later version open.
- You don't have SketchUp. You also get the model as STL, OBJ with textures, GLB, and DXF, and the texture pictures and the thumbnail as image files.
What you get
A .skp you can open, with components and groups, materials and textures, tags, the model's
units, texts, dimensions and guides; a shaded picture of the model; and a short report of the
file's condition that you can keep or send to whoever helps you. Nothing needs to be renamed
before uploading: .skb and .skp~ files are accepted directly, alone or in a ZIP.
If the backup is too old
The .skb is only one save behind. If you need something closer to your last work, look in
SketchUp's autosave folder (on Windows, AppData\Local\SketchUp\SketchUp 20xx\SketchUp\working,
which is hidden; on a Mac, Library/Application Support/SketchUp 20xx/SketchUp/Autosave) and
in the version history of the cloud folder the model lived in.
More about what this tool reads and writes: SketchUp File Repair and Converter (SKP to 2017, STL, OBJ).