Convert SLDPRT
to STL.

Updated 2026-10-16

To convert SLDPRT to STL, drop the .sldprt into the converter below and download an .stl your slicer opens. 5 conversions a day are free with no account, nothing is installed, and you do not need SOLIDWORKS. The STL is written in millimetres. If your slicer reads 3MF, the SLDPRT to 3MF conversion records the unit in the file as well.

5 conversions a day with no account. No card, no install, no CAD licence.

No account needed
Drop a SLDPRT file.sldprt · up to 200 MB

On our servers. No account: deleted within 24 hours. Signed in: kept until you delete them. Never shared or used for training.

ResultTessellated

The solid in the SLDPRT file is triangulated to produce the STL output. Multibody parts keep their bodies separate, with their names.

ChangesSLDPRT → STL

What changes between SLDPRT and STL

A SLDPRT holds an exact solid and the history behind it; an STL holds a list of flat triangles. The conversion keeps the shape and gives up the exactness: curved faces become fans of small facets, and flat ones stay flat.

Everything that is not shape is dropped. STL has no room for a unit, colour, material, feature tree or configuration. The file is written in millimetres, so choose millimetres if your slicer asks; a part that arrives 25.4 times too small or large was read as inches.

The step is one-way. An STL is the right file to print, and a poor one to edit: CAD software sees it as triangles, not as faces with radii. Keep the SLDPRT, or convert it to STEP as well, if the part may change. A part saved before SOLIDWORKS 2015, in the older format, converts here as well.

HowThree steps
  1. Drop your .sldprt file above — up to 200 MB without an account.
  2. STL is already selected as the output.
  3. Download the .stl. Without an account, files are deleted within 24 hours; signed in, they are kept until you delete them.
FormatsWhat you are holding

SOLIDWORKS part file (.sldprt)

A SLDPRT file is a single SOLIDWORKS part: the exact solid — true planes, cylinders and splines — plus its feature history, sketches, material and custom properties. It is proprietary, so nothing else on your machine may open it. Assemblies are SLDASM files. One SLDPRT can hold several bodies, and those should stay separate when converting.

You were sent a SLDPRT, do not have SOLIDWORKS, and need the geometry in something your CAD system, slicer or mesher opens.

STL file (stereolithography) (.stl)

STL is the lingua franca of 3D printing: a flat list of triangles. No unit, colour, material or history — a cylinder is a fan of flat strips. The missing unit is the classic cause of scale accidents. Every slicer and mesh tool reads it.

You are printing, meshing or sending to a bureau — where triangles are what is wanted.

Questions12 answered
How do I convert SLDPRT to STL without SOLIDWORKS?
Drop the .sldprt on this page, where STL is already selected, and download the .stl. Nothing is installed and no licence is involved.
Can my slicer open a SLDPRT directly?
No. PrusaSlicer, Bambu Studio, Cura and the rest read STL, 3MF, OBJ and sometimes STEP, but not SOLIDWORKS files.
Why is my STL the wrong size?
STL stores numbers with no unit. This file is in millimetres; set the slicer to millimetres, or use 3MF, which records the unit.
Can I edit the STL in CAD afterwards?
Only as triangles. For editable geometry convert the SLDPRT to STEP, which keeps the part's own true surfaces wherever they can be read.
Is the SLDPRT to STL converter free?
Yes. 5 conversions a day with no account and no card. A free account raises the limit and adds 25 credits.
Do I need SOLIDWORKS to convert a SLDPRT file?
No. The file opens and converts in the browser with nothing installed and no CAD licence.
How accurate is the STL mesh?
The part opens and comes back as a STL mesh, with nothing installed. The solid in the SLDPRT file is triangulated to produce the STL output. Multibody parts keep their bodies separate, with their names.
What happens to a multibody part?
Bodies stay separate and keep their names.
Will the STL file be the right size?
It is written in millimetres. STL records no unit, so choose millimetres if your slicer asks. 3MF records units in the file.
How big a file can I convert?
To a mesh format like STL: 300 MB with a free account, 200 MB without one. To STEP, Parasolid or SLDPRT: 140 MB, because rebuilding a solid takes about twice the memory of writing a mesh. Maker and Studio convert up to 830 MB and 380 MB — a large conversion on a paid plan gets the server to itself.
Is it safe to upload my SLDPRT file?
Files travel encrypted and are processed by machine on our own servers — no third parties, no ads or trackers, no AI training.
Is my SLDPRT file deleted after converting?
Without an account, the upload and the result are deleted within 24 hours. With an account, both stay in your files until you delete them; deleted files leave our servers within 24 hours.
Beyond convertingSame file, four workspaces

Keep the part open: fill it with a lattice, check it with FEA, texture a surface, or slice it into cut-ready sheets. These workspaces are in early access — create an account, then apply from inside the app.

Create free account See pricing

ReadWhy this works the way it does
AlsoOther ways in
MoreRelated conversions

Going the other way? Convert STL to SLDPRT.

Need it in an older SolidWorks? Save a part for an older release.

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