About STL Editor Online

STL Editor Online is a focused workspace for the moment between finding a 3D model and getting it ready to print.

Tools for the everyday adjustment

Use the STL editor to scale, rotate or move a whole model. Open the viewer for an inspection, the resizer for a precise fit, or the measurement tool for dimensions and mesh statistics. The 3MF to STL and STL to 3MF converters share the geometry engine and keep processing local.

Local by design

Your model is parsed and processed in your browser using a Web Worker. Three.js renders the preview. There is no model upload endpoint and no account requirement. Closing or refreshing the page clears the model and edit history; export anything you want to keep.

Clear about the limits

This version edits whole meshes. It does not provide CAD modeling, vertex editing or repair. A dedicated simplifier reduces triangles; SVG cross-sections create planar vector contours. Binary to ASCII and ASCII to binary encoding converters are also available. Dedicated converters support triangle-mesh 3MF packages. Input limits are 25 MiB and 400,000 expanded triangles. Very complex meshes may still be slow on devices with limited memory.

Check before you print

STL does not store physical units. This workspace treats coordinates as millimeters in the editing tools; the STL to 3MF converter also offers inch input. Binary STL export uses 32-bit coordinates. Volume estimates use mesh edge and winding checks, which cannot detect self-intersections. Review exported geometry in your slicer before manufacturing.

How do I get started?

Open any tool, choose a local STL or try the sample model, then export the result. Read our privacy policy for data-handling details or visit contact and feedback for a reproducible issue-report checklist.