Convert PNG to a 3D-printable STL — free, no signup, no upload
This tool converts a PNG into a height field by brightness and builds a solid, watertight STL relief. PNG transparency is flattened to white. Turn on Invert for a backlit lithophane. Everything runs in your browser — your image is never uploaded to a server.
How it works
1. Drop your image above. 2. Set the width (physical size), relief height (how deep the surface goes) and base (flat backing). 3. Pick a detail level, optionally toggle Invert for a lithophane, and preview in 3D. 4. Click Download STL.
Frequently asked questions
How do I convert an image to STL?
Drop an image above (or click Open), tweak the width, height and detail, preview it in 3D, then click Download STL. It all runs in your browser — nothing is uploaded.
What's the difference between a relief and a lithophane?
A relief raises the bright areas. A lithophane is the inverse — dark areas are made thicker — so when it's lit from behind, the image appears in light and shadow. Toggle Invert to switch.
Is the STL solid and printable?
Yes — it's built as a watertight solid with a flat base and side walls, ready to slice and print. Use the height and base controls to set the relief depth and backing thickness.
Is my image uploaded anywhere?
No. The image is read and converted entirely on your device; it never leaves your computer.