# UPDATETHUMBNAIL System Variable [GstarCAD 2020](Help%20System/GSTARCAD/2020/Index.md) → [System Variables](Help%20System/GSTARCAD/2020/System%20Variables/(System%20Variables).md) → [U](Help%20System/GSTARCAD/2020/System%20Variables/U/(U).md) ## Function Description: The UPDATETHUMBNAIL system variable is used to control the update of thumbnail preview for view and layout. | | | | --- | --- | | Type | Bitcode | | Saved in | Drawing | | Initial value | 15 | | Range | 0 \~ 16 | ## System Variable Value: **0:** do not update preview **1:** update preview of views in model space **2:** update preview of views in layout **4:** update preview of layout **8:** update preview when created, modified, or restored layout or views **16:**update preview when saving a drawing --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md) · [GstarCAD 2022](Help%20System/GSTARCAD/2022/System%20Variables/U/UPDATETHUMBNAIL%20System%20Variable.md)