Image to STL: turn a PNG or JPG into a 3D printable model

Converting an image to STL can mean two quite different things, depending on your picture and what you want to print. That's why the tool has two modes.

• Silhouette: the dark parts of the image (or the light parts, if you invert) become an outline that's extruded to an even height. Use it for logos, icons, drawings, silhouettes, keychains and wall art. The result has crisp edges and a flat top.
• Relief: every pixel's tone becomes a height. By default dark areas are high and light areas low; you can flip that. Photos, paintings and maps turn into a soft, coin-like plaque.

The image is turned into a triangle mesh in your browser; nothing is uploaded to a server. Download the result as STL or 3MF and open it in any slicer.

If your source is an SVG, use SVG to STL instead: it works directly with the vectors, so it's more accurate. If you want a picture that appears when lit from behind, that's a job for the lithophane maker.

In silhouette mode the image is first turned black and white using a threshold: anything darker becomes the raised part. A live preview shows the thresholded image, so you can see right away whether thin lines survive or merge.

• Threshold (10–245): if thin parts disappear, raise it; if gray specks from the background sneak in, lower it.
• Invert: raises the light part instead. Use it for a light logo on a dark background.
• Fill inner holes: keeps only the outer outline, so cutouts like the middle of an "O" disappear. Handy for solid shapes such as coasters or blanks.
• Extrusion height: 0.2 to 100 mm; 1.5–3 mm is typical for a keychain.
• Width: the silhouette's bounding-box width in mm; the height follows from the proportions.

For tracing, large images are scaled down to at most 700 pixels on the long side. That's plenty for a logo, since hairline details can't be printed with a 0.4 mm nozzle anyway. Transparent PNG areas count as white background.

You can put a base plate under the silhouette, square or with rounded corners. Set the plate thickness, the margin around the silhouette, the corner radius and a keyring hole of 3, 4, 5, 6 or 8 mm. A few clicks turn a logo into a keychain, a name tag or a backing for a fridge magnet.

With a base plate, the model has two parts, and you can download each as a separate STL: the base plate and the raised part. Load them into your slicer as one object and assign each to its own filament (AMS, MMU or another multi-material system).

A single-extruder printer can still do two colors: download the whole model in one piece and add a filament change in your slicer at the layer where the base plate ends. With a 1.6 mm plate and 0.2 mm layers, that's at 1.6 mm, the start of layer 9. The printer pauses, you swap filament, and it carries on.

In relief mode the image's tones become a height map. The settings:

Setting	What it does	Good start
Base thickness	thinnest part of the plate (0.4–5 mm)	1.2 mm
Relief height	how far the darkest point rises above the base (0.2–10 mm)	2 mm
Smoothing	blurs image noise before it becomes height (0–4 px)	1 px
Frame	full-height rim around the picture (0–10 mm)	0–3 mm
Resolution (point spacing)	distance between sample points: 0.2 / 0.3 / 0.5 / 1 mm	0.3 mm
Inverted	light areas become high	off

Worked example: a 4:3 photo at 80 mm wide (about 3.1 in) comes out 60 mm tall. With a 1.2 mm base and 2 mm of relief, the thickest point is 3.2 mm. If the picture averages mid-gray, the average thickness is about 2.2 mm, so the volume is 80 × 60 × 2.2 ≈ 10,560 mm³ ≈ 10.6 cm³, or about 13 g of solid PLA (1.24 g/cm³). The tool calculates the exact figure from the finished mesh and shows a 100%-infill gram estimate next to the size and triangle count.

At 0.2 mm spacing a large print would need millions of points; if it's too many, the tool asks you to pick a coarser spacing. For a 0.4 mm nozzle, 0.3 mm is a good balance between detail and file size.

• For silhouettes: a high-contrast, single-color logo or drawing on a clean white or transparent background. JPG compression can leave a gray halo around lines; the threshold handles that.
• For thin lines: the narrowest part should be at least 0.8–1 mm at final size, or your slicer will drop it. Scale a 700 px wide silhouette to 80 mm and a 2 px line becomes about 0.23 mm, which is too thin.
• For reliefs: a well-lit, contrasty photo with a simple background. A very dark photo ends up high almost everywhere; an overexposed one, almost flat.
• For faces: a relief follows tones, not real depth, so a portrait looks graphic rather than sculpted.

Print silhouettes lying flat, no supports. Print reliefs flat too, plate side down; 0.12–0.16 mm layers make the soft gradients smoother. To double-check size or filament use, open the result in the STL viewer.