STL EDITOR · FREE · NO UPLOAD
STL Editor — Scale, Rotate & Fix Before You Print
Resize to exact dimensions, rotate onto the build plate, mirror, and center — all in the browser. Nothing uploaded. Export the edited model as STL, OBJ, or GLB.
What this editor does
Most STL files need a quick adjustment before slicing: the model is the wrong size, facing the wrong way, or not centered on the build plate. This stl editor handles those pre-print fixes without opening a full CAD program or slicer.
Scale to dimensions
Type the target size in millimeters — proportional or per-axis.
Rotate for print orientation
Flip the model onto its flattest face to minimize supports.
Mirror
Flip along any axis — useful for making left/right pairs.
Center on build plate
One click to re-center after transforms.
These transforms modify geometry positions without changing triangle count or topology. The original file on your device is never touched — only the in-browser copy changes. Export when you are done.
FAQ
Is my STL file uploaded to a server?+
No. The editor runs entirely in this tab with JavaScript and WebGL. There is no upload endpoint — the file never leaves your device. Editing and export both work offline once the page has loaded.
Can I resize an STL to exact dimensions?+
Yes. The dimension fields show the current size in millimeters. Type the target dimension and press Enter — the model scales to match. With proportional lock on (the default), all three axes scale together so the shape is preserved.
How do I orient my model for 3D printing?+
Use the Rotate 90° buttons to flip the model onto its flattest face. The grid in the viewport represents the build plate. After rotating, click Center to re-align the model to the plate.
Does editing change the triangle count?+
No. The free tools (scale, rotate, mirror, center) transform existing geometry without adding or removing triangles. The mesh topology stays the same — only positions change.
Can I undo changes?+
Not yet in the current version. If you need to start over, reload the file. The original file on your device is never modified — only the in-browser copy changes.
What are the Pro tools?+
Pro tools — face selection, hole filling, cut planes, mesh smoothing, and hollowing — are in development. They will be part of STL Mesh Pro, a paid tier for users who need mesh editing beyond basic transforms.