STL to G-code Converter PRO
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Convert 3D printer STL files to G-code instantly — free browser-based slicer with layer preview and downloadable G-code.
🖨 Click to upload an STL file
input type="file" id="sgFile" accept=".stl" style="display:none" onchange="sgLoad(event)" aria-label="Sg file">
What is STL to G-code?
STL is the standard 3D model format for printing — a shell of triangles. A 3D printer can't print triangles directly; it needs G-code: line-by-line instructions (move, extrude, layer). Slicing converts one to the other.
This free browser slicer reads your STL, slices it into layers, generates real G-code (G21/G90/G0/G1 with extrusion), and shows a top-down layer preview — no software install needed.
How slicing works
The slicer intersects the model with horizontal planes at each layer height, collects the outline segments, chains them into closed paths, and emits G1 moves with extrusion values. Layer height and feed speed are adjustable.
How to Use
- Upload your STL file (binary or ASCII)
- Set layer height and print speed
- Click Slice — see stats and layer preview
- Download the G-code file
Features
🖨 Real G-codeValid G21/G90/G0/G1 output with E values.
📐 AdjustableLayer height and feed speed controls.
👁 PreviewTop-down layer visualization.
⭐ PRO FeaturePart of the Tooly Pro toolkit.
Frequently Asked Questions
What G-code dialect does this produce?
Standard Marlin-style G-code (G21 mm, G90 absolute, G0/G1 moves with E extrusion) — compatible with most desktop 3D printers.
Can I slice any STL file?
Yes — both binary and ASCII STL files are supported. The slicer generates perimeter-only paths; complex overhangs may need a full slicer like Cura.
Is STL to G-code free?
Free for 3 slices per day; unlimited with Tooly Pro (€10/month).