Convert SVG to STEP
This is the best case on the whole site for mesh-to-CAD conversion, and it is worth knowing why. An SVG given a thickness is made entirely of flat surfaces — a top, a bottom and walls — so nothing is approximated and the merge has everything to work with. You get a small, clean STEP solid with about as many faces as the shape has sides.
Drag a 3D file here, or.
This page is set up for SVG files. Other formats we can read work here too.
The file is read on your own computer. It is never uploaded.
Your file is read by your own browser and never sent to a server. There is no upload, no account and no copy of your model anywhere but on your computer.
Why this one comes out well
Every other page in this group has to explain that curves arrive faceted. Here there are no curves to lose. An extruded drawing has a flat top, a flat bottom and a wall standing on every segment of the outline, and that is exactly what a STEP file is good at describing.
The top and bottom merge into one face each — including their holes, so a letter O comes out as a face with a hole in it rather than a ring of triangles. The walls stay as one face per straight segment of the path. The result is a file of a few kilobytes that a CAD program opens instantly and whose faces you can click and select individually.
The one approximation is in the curves of the drawing itself. An SVG arc or Bézier has to be turned into straight segments before it can be given a thickness, so a circle in the drawing becomes a many-sided polygon in the solid. That is the same compromise every laser and CNC workflow makes, and at the resolution used here the segments are far below what any machine can cut.
What you get is still a faceted solid rather than a parametric CAD model. There is no sketch inside it to reopen and no extrude whose height you can retype — if you want a different thickness, come back to the SVG and convert it again. On this pair that costs nothing, which is why it matters less here than anywhere else on the site.
Thickness is the whole decision
The SVG is flat. What the STEP file will be is entirely up to the thickness box, and there is no right answer the drawing could have told us.
Three millimetres is a sturdy sign, a stencil or a keyring. Six to ten is a bracket you can load. One or two is a shim or an inlay. Type a number, watch the model in the 3D view, and read the measurements under it before converting.
The scale box resizes the drawing before the thickness is applied, and it is frequently needed: SVG files from web design tools are measured in pixels, and a drawing that is 200 pixels across is 200 units across here. Set it so the width under the 3D view is the width you want the real part to be.
Only closed paths become solid
A shape needs an inside to be given a thickness. A line, an open curve or a path left unclosed has no inside, so it cannot be extruded, and it is skipped rather than guessed at. You are told how many paths were skipped, so silence means everything worked.
If your drawing came out empty or missing pieces, this is almost always why. In Inkscape, select the paths and use Path then Union, or close them by joining their end nodes. In Illustrator, make sure the shapes are closed paths rather than strokes. A stroke is a line with a width, not a shape, and it has no inside for anything to fill.
Holes work as you would expect. A path inside another path becomes a hole, which is how the counter of a letter O or the middle of a washer comes out right — and in the STEP file it is a genuine hole in a genuine face, which is what lets a CAD program treat it as one.
What this is for
Taking a logo, a nameplate or a gasket outline from a drawing program into CAD so it can be part of a real design — cut into a face, used as a boss, or subtracted from a block.
Giving a machine shop a 3D solid when all you have is a 2D drawing. A STEP solid with a stated thickness removes an entire conversation.
Building a part around a shape you only have as artwork: a bezel, a faceplate, a stencil holder.
If you want to cut the shape flat rather than make a solid of it, you want DXF rather than STEP, and a laser cutter would rather have the 2D outline.
What survives, and what does not
Kept in the STEP file
- The outline of every closed path, as real CAD faces with real edges
- Holes, as genuine holes in a face rather than a ring of triangles
- The thickness and scale you set, in the unit you choose
- A clean, small file — this pair produces the smallest STEP on the site
Lost on the way
- Open paths and strokes, which have no inside to fill — you are told how many were skipped
- Colours, fills and gradients: a CAD solid has no such thing
- True curves — the drawing’s arcs become many short straight edges, as they do for any machine
How to convert SVG to STEP
Drop the .svg in
Closed paths become shapes. Anything open is skipped and counted, so you will know if something is missing.
Set the thickness
This is the decision the drawing cannot make for you. 3 mm is a sign or keyring, 6 to 10 mm a bracket. The model in the viewport updates as you type.
Fix the scale
Drawings from web tools are in pixels. Set the scale so the width under the 3D view is the real width you want, in millimetres.
Convert and open in CAD
The file will be small — usually a few kilobytes — and every face in it is a real face you can select and work with.
SVG and STEP compared
| Property | SVG.svg | STEP.step .stp |
|---|---|---|
| File contents | XML. A text description of shapes, readable and editable by hand. | Plain text in the ISO 10303-21 exchange form. Readable, and enormous. |
| Geometry | Flat paths: lines, arcs, and cubic and quadratic Bézier curves. | Exact surfaces: planes, cylinders, cones, spheres, NURBS. Not triangles. |
| Units | Real units are allowed — mm, cm, in — but most files use bare user units. | Recorded in the file, as a full unit and tolerance context. |
| Colour and texture | Fills, strokes, gradients and patterns, none of which describe a solid. | Colour per face or per solid, through the AP214 and AP242 styling entities. |
| Separate objects | Groups and layers, with ids and names on both. | An assembly tree of named parts, each with its own placement. |
| Published by | The W3C, 1999. Version 1.1 is what tools write; SVG 2 is still arriving. | ISO 10303, from 1994. AP242 is the current application protocol. |
| Written by | Illustrator, Inkscape, Affinity Designer, Figma and every drawing program. | SolidWorks, Fusion 360, Inventor, CATIA, FreeCAD, Onshape — every serious CAD program. |
Questions
- Why does this pair give a better STEP than STL to STEP does?
- Because an extruded drawing is made entirely of flat surfaces, so nothing has to be approximated. Converting an STL means accepting whatever facets were baked into it; here the solid is built from the outline directly, and every face in it is a genuine flat face.
- My drawing came out empty.
- The paths are open, or they are strokes rather than shapes. A stroke is a line with a width and has no inside. In Inkscape use Path then Union, or Stroke to Path first; in Illustrator make sure you have closed paths.
- Are the circles real circles in the CAD file?
- No. The drawing’s curves are turned into short straight segments before the thickness is applied, so a circle becomes a many-sided polygon. The segments are far finer than any machine can cut, but if you need a mathematically exact circle you should draw it in CAD.
- Can I make the shape a different thickness later?
- Not by editing the STEP — it holds the solid, not the drawing. Keep the SVG and convert it again with a new thickness. It takes seconds.
- Is this a real CAD model I can edit?
- It is a real solid: your CAD program can cut it, add to it, measure it, section it and put it in an assembly. It is not a parametric model. There is no sketch to change, no extrude to edit and no dimension to type a new number into, because none of that is in a mesh to be recovered. If you need those, the model has to be drawn again from measurements.
- Does my file get uploaded?
- No. The whole conversion runs inside your browser, and nothing is sent anywhere. That matters more here than on most pages: a part being taken into CAD is usually somebody’s product.