STEP to STL Converter
LocalConvert STEP to STL for 3D printing in your browser — free, no upload, no sign-in. Binary STL with four tessellation presets and mm/cm/inch output units.
Drag files here, or click to browse
Supports STEP, STP
Choose fileGeometry values are treated as millimeters (OCCT output); cm = ×0.1, inch = ÷25.4, multiplied by the custom scale. If your source model is not in mm, correct it with the custom scale.
Higher presets mean more triangles, larger files and slower conversion; Standard suits most 3D printing. Binary STL is roughly 50 bytes per triangle; ASCII is a text format (larger, human-readable). Parsed values are millimeters (OCCT converts the STEP file's units to mm) — cm/inch output is a numeric conversion (×0.1 / ÷25.4).
STEP → STL (OCCT triangulation in your browser; files are not uploaded)
Per-file cap: see the dropzone validation; very large models are bounded by browser memory.
Preview first: conversion and download happen only after you click the button above. Files are not uploaded.
What is it? STEP to STL Converter converts STEP CAD models to STL meshes ready for 3D printing, running in the browser with no upload. Parsed dimensions are millimeters (OCCT converts the file's units), so slicers read the modeled size directly.
TL;DR: STEP to STL tessellates STEP models at four precision levels and exports STL ready for 3D printing, with units resolved to millimeters. Drop a .step, pick a precision, preview, then convert and download — straight into your slicer. Free with no sign-in; parsed locally, nothing is uploaded.
How to use
- Drop or select a .step/.stp file (or click "Try a sample") — the model previews on the page (orbit to inspect).
- Optionally pick a tessellation preset: Draft / Standard / High / Ultra, plus the encoding (binary/ASCII), output unit and filename.
- Click Convert & download — the .stl saves to your downloads.
FAQ
Is the mesh watertight?
Tessellation generally produces a printable mesh; run Mesh Doctor if your slicer reports issues.
Will the STL be the right size?
Yes for most files: parsing converts the STEP file's units to millimeters (verified: an inch-declared 10-unit cube measures 254), so slicers that assume mm read the modeled size. If in doubt, verify one known dimension after import.
Is there a file size limit?
The per-file cap is shown on the page; split large assemblies first.
What happens to assemblies?
They merge into one mesh; structure and part names are not kept.
Can I convert STL back to STEP?
Not supported — no reliable B-Rep reconstruction runs in the browser; keep your original STEP.
Which slicers can open the STL?
Any major slicer — Cura, PrusaSlicer, Bambu Studio and friends import the binary STL directly.
Is it local?
Yes, conversion is local.
Which STEP versions are supported?
STEP AP203, AP214 and AP242 — the application protocols most CAD systems export. Regular solids and assembly structures load; older or rarely used entity types usually parse, but some may be approximated during tessellation.
Do I need CAD software like SolidWorks, NX, Inventor or Creo?
No. Everything runs in your browser tab — no CAD license, plug-in or sign-in. That fits the common case where a supplier or customer sends a STEP file and you only need a printable STL for your slicer, including NDA-bound work.
Why is the STL larger than the STEP file?
STL replaces every curved surface with flat triangles, so file size grows with the High and Ultra presets. Draft or Standard keeps meshes small; the output is binary STL by default, the compact variant slicers accept directly.
Is it free? Any watermark?
Free, no watermark, no account — with a daily free allowance. Conversion runs locally in your browser, so there is no per-file upload to meter.
Examples
- Drop in a STEP file (or try the sample) → pick precision → convert & download STL, ready for slicing
Supported formats
Limitations
- Tessellation precision presets: Draft / Standard / High / Ultra (more faces at higher quality).
- Large models are memory-bound; keep STEP files under 100 MB and split large assemblies. The per-file cap is shown on the page.
- Output is a triangle mesh (STL) — exact B-Rep is not preserved.
- Units: parsing converts the STEP file's units to millimeters (an inch-declared file measures ×25.4); STL values are millimeters. cm/inch outputs are numeric conversions via the output-unit option.
- Parsed locally (OCCT WASM); files are not uploaded.
Privacy
Privacy first: this tool runs entirely in your browser — your input and files never leave your device, and everything is cleared when you close the page.
Related tools
Standards & comparison
| Dimension | Vecaria (this tool) | Online converters (cloud) | Desktop professional CAD |
|---|---|---|---|
| Privacy | Runs locally in your browser; the file is not uploaded | You upload the file to a third-party server | Runs locally |
| Wait | No queue — as fast as your own device | Upload plus cloud queue | Local application startup |
| Standards support | ISO 10303-21 (STEP) · AP203 / AP214 / AP242 | Varies by service, often older subsets | Full vendor protocol sets |
| Install footprint | 0 MB — runs in the browser | 0 MB | Several GB of storage |