Free online converter · no sign-up
X_T to STL converter.
To turn a Parasolid .x_t file into an STL for 3D printing, drop it below, pick Standard or Fine, and download the .stl, free and with no account. The mesh is made in your browser, so the file never leaves your computer unless you choose to send it to us, and it is checked against the solid before you can download it. Not every file converts: what cannot be rebuilt exactly is refused or left out, and the page says which.
Your file never leaves your computer unless you choose to send it to us: the conversion runs in your browser.
How to convert X_T to STL
- Drop the file. Drop your .x_t file on the box above, or choose it from your computer.
- Pick a resolution. Convert to starts on Standard (0.05 mm). Fine (0.01 mm) is in the same menu.
- Press Convert. The converter rebuilds the solid, meshes it, and measures the mesh against it.
- Download the STL. Binary STL in millimetres. If a part of an assembly was left out, the page names it.
| X_T to STL | What happens |
|---|---|
| Reads | Parasolid text files (.x_t), parts and assemblies, from Parasolid 12 on. |
| Writes | Binary STL, in millimetres, at Standard (0.05 mm, 5 degrees) or Fine (0.01 mm, 1 degree) resolution. |
| Keeps | The shape, within the tolerance you pick, and every part of an assembly that can be rebuilt exactly, in place. |
| Drops | True curves, which become flat triangles, plus the assembly tree, part names and colours. |
| Checks | The mesh's volume and bounding box, against the solid. Not that the mesh is closed. |
| Costs | Free, with no account and no limit on how many files you convert. |
Why a slicer needs the STL
The common slicers do not open Parasolid files. An X_T describes exact surfaces, and a slicer wants triangles. If your slicer reads STEP, as PrusaSlicer and Bambu Studio do, X_T to STEP is worth trying first, because the slicer then makes its own mesh from the exact faces. For everything else that wants a mesh, such as an older slicer, a viewer or a 3D printing service's upload form, this is the file.
Standard or Fine for a print
Standard stays within 0.05 mm of the true surface, below the layer height of a typical printer, and it is the one to start with. Fine holds 0.01 mm and 1 degree, and is for a large part with gentle curves where facets would show. The bracket below made 14,288 triangles and a 698 KB STL at Standard in 0.7 seconds, and 280,832 triangles and a 13.4 MB STL at Fine in 11 seconds.
Assemblies become one mesh
Every part of an assembly that the converter can rebuild goes into the one STL, where the assembly places it, and a part used three times is there three times. STL has no way to say which triangles belong to which part, so to print parts separately, export them separately. A part that cannot be rebuilt exactly is left out, the page says which, and the file's name counts what is there: frame (27 of 31 parts).stl.
How the mesh is checked
The STL is read back and measured against the solid rebuilt from your X_T. Its volume may differ only by the surface area times the tolerance, and its bounding box must match to within that tolerance. For an assembly converted without a part, it compares the parts converted. Those two measurements are all the check makes: it does not prove the mesh is closed, and a small missing face can pass.
A measured example
A 120 x 80 x 30 mm bracket modelled in SOLIDWORKS 2024 (a plate with a filleted, chamfered boss and five holes) is the part behind the numbers above, from a 13 KB X_T, on a desktop PC on 5 November 2026. The check line read: "Verified: the STL was read back. Its mesh agrees with the solid on volume to 0.01% and size exactly, at Standard resolution (0.05 mm, 5°)." A file this simple is the easy case, not the typical one.
Parasolid files fail more often here than any other format. When an X_T will not convert says why, and what to do instead.
Credits and licences for the projects the converter is built on are on the converter page.
Questions
Will the STL be watertight?
A solid normally comes out as a closed mesh, but the check measures only volume and size, so it does not prove that, and a small missing face can pass. If it matters, run the STL through your slicer's mesh check.
What size will my print be?
The size of the part. The STL is written in millimetres whatever units the X_T came from, and slicers assume millimetres.
Can I make an X_T from the STL afterwards?
No. The converter does not write Parasolid, and the exact curves are gone once a part is a mesh. Keep the X_T.
Every conversion
| From | To STEP | To IGES | To STL |
|---|---|---|---|
| SLDPRT | SLDPRT to STEP | SLDPRT to IGES | SLDPRT to STL |
| X_T | X_T to STEP | X_T to IGES | X_T to STL |
| X_B | X_B to STEP | X_B to IGES | X_B to STL |
| STEP (.stp) | Already STEP | STEP to IGES | STEP to STL |
| IGES (.igs) | IGES to STEP | Already IGES | IGES to STL |
| STL | STL to STEP | STL to IGES | Already STL |
Quoting laser-cut parts from files like these?
Lasertally is Windows software for fabrication shops. It opens STEP, IGES, DXF and NC1 files, measures the pierces, cut length and bends off the geometry, and prices the part on your own rate card.