Checked 2026-10-01 against each tool's own pages
The best free route is to ask whoever sent the SLDPRT to export a STEP. Without them, an online converter or Onshape's free plan will produce one; eDrawings and Autodesk Viewer open the part but do not save STEP, and FreeCAD does not read SLDPRT. No route carries the SOLIDWORKS feature tree.
| Option | Gives you a STEP? | Cost | Account | Where your file goes | Good at | The catch |
|---|---|---|---|---|---|---|
| Ask the sender | Yes, exact | Free | No | Their machine | Exported by SOLIDWORKS itself, so it is as faithful as a STEP gets. | Needs someone with SOLIDWORKS who still has the file. |
| MeshWeavemeshweave.app/privacymeshweave.app/pricing | Yes, exact surfaces | Free, 2 solid conversions a day without an account | No | Our own servers. Without an account, deleted within 24 hours; never shared or used to train AI. | Nothing to install; multibody parts keep their bodies; also saves a part for an older SOLIDWORKS. | No feature tree (true of every route). 200 MB per file on the free tier. |
| Onshape (free plan)onshape.comcad.onshape.com | Yes | Free for personal, non-commercial use | Yes | Onshape's cloud. On the free plan, every document is public. | A full CAD system: the imported part can be edited and exported to many formats. | Public documents rule it out for anything confidential; commercial use needs a paid plan. |
| eDrawings Vieweredrawingsviewer.com | No: it saves STL and images, not STEP | Free | Not stated | Your computer or phone | Made by the SOLIDWORKS vendor, so it opens parts and assemblies faithfully, with measurement and sections. | A viewer: fine for looking and measuring, not for getting a STEP. |
| Autodesk Viewerviewer.autodesk.com | No: view only | Free | Not stated for uploading | Uploaded to Autodesk's cloud | Opens SLDPRT and 80+ other formats in any browser, with shareable markup. | No export was found, so it cannot give you a STEP. |
| AnyConvanyconv.comanyconv.com | Not offered: its SLDPRT converter lists STL and OBJ | Free | No | Its servers (Germany, Finland); deleted usually within 1 hour, per its policy | Simple, free, batch uploads, 100 MB files, and hundreds of non-CAD formats. | Mesh output from a SLDPRT, not a STEP solid. |
| Convert3Dconvert3d.orgconvert3d.org | Listed (SLDPRT to STP) | Free | No | In your browser, per the site: files are not uploaded | Runs on your own machine, with a very wide format list. | Whether the STEP carries true surfaces or facets is not stated; file-size limit not stated. |
| ABViewercadsofttools.com | Yes (desktop) | 30-day free trial, then paid | Not stated | Your computer | Desktop converter with batch mode, measurement and strong 2D DWG/DXF tools. | A desktop install; free only for the trial. |
| CAD Exchanger Labcadexchanger.com | Yes (desktop) | Paid licence | Not stated | Your computer | 30+ formats with exact geometry, assembly structure and PMI; Windows, macOS and Linux. | Paid. Its free online viewer views files but this check found no conversion in it. |
| FreeCADwiki.freecad.org | No: it does not read SLDPRT | Free, open source | No | Your computer | A full parametric modeller with excellent STEP support once you have a STEP. | SLDPRT is not among its import formats, so it is the next step, not the converter. |
"Not stated" means the tool's own pages did not say, on 2026-10-01. If you run one of these tools and something here is wrong or out of date, write to hello@meshweave.app and it will be corrected.