Choose an SVG, set its size and a thickness, and download a binary STL: the filled shapes raised into one flat-topped solid, checked to be watertight.

Free, no account. The file is read by code running in your browser. It is not uploaded, and nothing about it is stored.

How to turn an SVG into an STL

Choose an SVG file, drop one on the box, or paste its code.
Check the width and height in millimetres and type the size you want to print.
Set the thickness: how far the shapes rise from the bed.
Turn the preview to check the solid, read the volume and the watertight line, and download the STL.

What becomes solid

Every filled shape in the SVG is raised straight up from a flat base, like dough cut with a cutter. Shapes that overlap are merged first, so two overlapping circles become one piece and not two solids pushed through each other. Holes follow the SVG: the counter of a letter O, or a window cut with the even-odd fill rule, is a hole through the solid.

Colour plays no part. A white shape is as solid as a black one, and a white shape laid over a black one does not cut a hole in it, as it seems to on screen. If your SVG has a background rectangle, delete it first or you will get a slab.

Lines are left out unless you tick “Make strokes solid too”. Each stroke then becomes a band of its own width, with the corners and ends the SVG gives it (round, bevelled or mitred; butt, round or square). Dashed strokes are made solid along their whole length. For a drawing made only of lines the box is ticked for you.

Size, thickness and what prints

An STL holds no unit, and slicers read its numbers as millimetres, which is what this tool writes. The width and height come from the SVG; a size in pixels is converted at 96 pixels to the inch. Curves are cut into straight pieces no further than the curve tolerance from the true curve: 0.05 mm unless you change it, which is finer than a printer’s nozzle can show.

Some thicknesses that work: 3 mm for a keychain or a tag, 2 mm for a sign letter to glue down, 12 to 15 mm for a cookie cutter. A wall must be at least as wide as your nozzle to print at all, and twice that to be strong: with the common 0.4 mm nozzle, draw cutter walls and thin strokes 0.8 mm wide or more. For a stamp, tick “Mirror” so the print reads the right way round when pressed.

A mesh the slicer accepts

The solid is closed on every side: a top, a bottom at height 0 and upright walls, with every edge shared by exactly two triangles and every triangle facing outwards. The page counts the edges of the finished mesh and tells you the result, so you can see it is watertight before you download.

Where two shapes meet at a single point, as the squares of a QR code do at their corners, a mesh would have one edge shared by four walls, which slicers report as an error. When that happens everything is grown by 0.002 mm, far less than a printer can show, so the point becomes a real join; a note says so.

The file is a binary STL: an 84 byte header, then 50 bytes for each triangle. A simple badge is a few hundred triangles; a detailed drawing with many curves can run to a few hundred thousand.

What it does not do

More than one height. Everything rises to the same thickness. There is no raised lettering on a plate, no bevel and no dome.
A base plate. Separate shapes stay separate pieces. To hold letters together, draw a filled shape behind them in the SVG.
Text. Convert text to paths in your drawing program first.
Pictures, clip paths and masks. Embedded pictures are skipped; clipped and masked shapes are raised whole.

Questions

How do I make a cookie cutter from an SVG?

Draw the outline as a line with no fill, about 1 mm wide. Tick “Make strokes solid too” and set the thickness to 12 to 15 mm. You get a plain wall of that width; it has no wider rim on top to press on.

Why did I get a solid block?

The SVG has a filled rectangle behind the drawing. On screen it is the background; here it is the biggest shape. Delete it in your drawing program, or give it no fill.

Can I raise letters from a plate, at two heights?

Not in one file. Save the plate and the letters as two SVGs on the same page size and convert each at its own thickness. Both keep their place on the page, so in a slicer that loads them as parts of one object they line up.

Does the STL need repairing before printing?

It should not. The page checks every edge of the mesh and says whether it is watertight. If it says no, it tells you how many edges are at fault, and most slicers will repair them on opening.

SVG to STL converter