Free browser tool
Convert PNG to STL
Turn a PNG into a printable relief or extruded model without uploading it.
Private by design. Your PNG is processed locally in your browser.
Your 3D preview will appear here.
How it works
How to convert PNG to STL
The PNG to STL converter reads the image locally and creates a printable relief or extrusion without uploading the file.
- 1Choose a PNG
Upload a PNG up to 20 MB and 4096 × 4096 pixels.
- 2Preview the model
Transparent artwork starts as Extrude; opaque artwork starts as Relief.
- 3Download the STL
Save the binary STL and check it in your slicer.
Alpha channel
How transparent PNGs become STL shapes
A transparent PNG contains an alpha channel that describes how visible each pixel is. When meaningful transparency is present, IntoSTL initially selects Extrude and uses that alpha-defined foreground to create a solid shape.
Transparent areas are left outside the solid, so clear gaps and supported internal holes can remain open. This is direct alpha-channel handling, not background removal or vector tracing.
Choose a style
Relief or Extrude for PNG?
Relief is the useful starting point for an opaque or photo-like PNG: pixel brightness becomes surface height. Extrude gives a clear foreground uniform depth.
A high-contrast opaque image can also use Extrude, where a simple light-background threshold separates the foreground. You can change Style, Depth and Size before downloading.
Source quality
What PNG images work best?
Use a clean image with a clearly defined subject. Smooth, intentional transparency works better than faint edge noise, while strong tonal contrast helps an opaque PNG produce a readable relief.
For artwork whose main purpose is an extruded mark, icon or brand shape, the logo to STL guide has more focused preparation advice. For broader image choices, see Image to STL.
Common questions
PNG to STL FAQ
Does PNG transparency affect the STL?
Yes. Meaningful transparency automatically selects Extrude, where the alpha channel defines the solid shape.
Should I use Relief or Extrude for a PNG?
Use Relief when brightness should control height. Use Extrude when a clearly separated foreground should become a solid shape.
Are transparent pixels kept as empty space?
In Extrude mode, transparent areas are excluded from the solid shape, so clear holes and gaps can remain open.
Is my PNG uploaded?
No. IntoSTL reads and converts the PNG locally in your browser.