Centerline Trace
One pass down the middle of each stroke, for engraving, V-carving and pen plotting. An outline trace would run down both sides instead.
Works with: LightBurn · Fusion 360 · AutoCAD · GRBL · Mach3
Drop several files at once to convert the whole folder in one pass. Got a different format? A PNG, JPG, HEIC, PDF, SVG or DXF still comes out as SVG.
× removes a colour and its shapes; click a swatch to change it. Every format follows.
- Runs in this tab
- No sign-up
- Full resolution out
Batch
Every file is traced on its own at its own resolution, with the settings in the panel. A file converted here comes out identical to the same file converted by itself.
Every format
Conversion settings
Trace settings
Full-colour trace for print and web.
Fine-tune
Raise it to clear dust, grain and stray dots; 0 keeps every mark.
Untick for pixel art: the outline then follows every pixel edge.
With Remove background: how close a colour must be to the background to go with it.
Machine output
Height follows the source aspect ratio.
Laser and Router follow the traced outlines. Engrave photo burns the picture itself, line by line, for photos and portraits.
Heat transfer vinyl is pressed face down, so it has to be cut mirrored. The second box is the overcut in millimetres: a drag knife starts each shape pointing the wrong way, and running past the start covers that stretch properly so the piece weeds out clean.
Beam or bit width. Left at zero the tool runs down the centre of the line, so a part finishes one tool width undersize. Set it and the path is offset by half, with holes offset the opposite way.
Holes before the part that holds them, so nothing comes loose while there is still cutting to do. Also shortens the travel between cuts.
See it on your product
Put this artwork on a 3D mug, tumbler, sign, phone case or canvas, turn it all the way round, or drop it onto a photograph of your own blank. The preview page has the product picker, the colours and the placement controls.
Open the preview and renderHow it works
Upload your artwork
Mono mode is preset, a single cut outline is what a machine wants, not colour layers.
Set your real size
Choose millimetres or inches and the finished width. The file carries physical units, not pixels.
Check the preview, then cut
Inspect the toolpath before you download. Cuts draw solid, rapids dashed.
Centerline trace: one line down the middle of every stroke
Centerline trace draws one path down the middle of each stroke, where an outline trace draws two, one down each side. That single line is what a laser engraver, pen plotter, drag knife for scoring, or V-bit needs: one pass, not a hollow shape.
Centerline tracing is the hard kind of tracing, which is why most free tools skip it. This centerline trace online free tool runs in your browser and exports SVG, DXF or G-code.
People also search for
- single line svg
- stroke vectorization
- engraving single line
- pen plotter svg
- handwriting to single line
Why it matters
Correct units, stated in the file
DXF exports write $INSUNITS. Without it a part imports at 25.4x the intended size, which is the single most common cause of a ruined first cut.
Y axis the right way up
SVG puts +Y down the screen; CAD and CAM put it up. We flip it. Exporting without that correction gives a part mirrored about the X axis, it cuts, but backwards.
Closed contours
A cutter following an open outline leaves the part attached. Outlines are closed, and anything that is not is flagged before you download.
Conservative G-code
The tool is disengaged before every reposition, retracted before every rapid, and the program always ends tool-off and clear.
Questions
What is the difference between outline and centerline tracing?
An outline trace follows the edges of a stroke and gives a closed shape with a thickness, good for cutting or filling. A centerline trace follows the middle and gives a single open line, good for engraving, plotting or V-carving.
Can I centerline trace a signature or a stamp?
Yes. Scan or photograph the signature or stamp in dark ink on white, upload it, and each stroke comes out as a single line. That is how a signature is engraved on jewellery, a memorial plate or a pen.
Why does my centerline trace have small branches?
Thick blobs and ink spots have their own middle. Raise the detail filter or clean the scan before tracing.
What units does the file use?
Whichever you pick, millimetres or inches, and the choice is written into the file header so the receiving software does not have to guess.
Will this work with my laser?
DXF is written as R2000 by default, which LightBurn, Fusion, AutoCAD and current CAM packages all read. There is an R12 option for older controllers that predate LWPOLYLINE.
Can I trust the G-code?
Preview the toolpath first, and dry-run any new program above the material. The generated code assumes you have set your own work origin, and it homes nothing.
Reading on SVG and machine files
Image to SVG: here, by hand, or on a server
| Veconvert | Illustrator, by hand | A paid vectorizer | |
|---|---|---|---|
| What it costs | Free preview; one file for $3.49 as a guest ($3.99 for technical files), $6.50 in bulk | $23 a month | $8–15 a month |
| How long it takes | Seconds | 30–60 minutes by hand | Seconds |
| Skill needed | None. Drop the file | You have to be able to draw | None |
| Where your file goes | Nowhere. It stays in this tab | Stays on your machine | Uploaded to a server |
| SVG with real units | Yes | Yes, with setup | Usually pixels |
| Machine files too | DXF, G-code, PLT, STL from the same trace | Separate export each time | Rarely |
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