Convert TM-33 to STL (Free)
Also converts OBJ, GLB, USDZ, PNG, HTML from the same file.
Runs in your browser. No upload, no signup, nothing to install.
Also from Innerscene: Circadian Lab, a free lighting calculator for room illuminance, melanopic EML, and glare.
How to convert TM-33 to STL
- 1
Open your .tm33 file
Drag it onto the viewer above, or click "Open a TM-33 File". Files up to 200 MB open directly; the parse runs in a worker so the page stays responsive.
- 2
Pick Stereolithography in the Export menu
Click Export in the toolbar, then STL (.stl).
- 3
Download
The .stl is written in the browser and saved straight to your downloads folder. No queue, no email, no watermark.
What survives the conversion
A file conversion is a translation, and formats do not carry the same things. Here is exactly what moves from TM-33 into STL, and what does not.
| Geometry | Kept | Both formats store triangle meshes, so the shape transfers directly. |
|---|---|---|
| Colors and materials | Dropped | STL has no concept of color or materials, so the per-vertex color in your TM-33 file are not written. The geometry is unaffected. |
| Layers and structure | Dropped | STL is a single flat body with no layers or named parts. Everything merges into one object. If you need the structure, export to GLB, OBJ, DXF instead. |
| Units and scale | Dropped | STL stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks. |
What the STL writer emits: Binary STL, one triangle record per face, positions written verbatim in meters.
The source: IES TM-33 photometric XML (.tm33)
The luminaire’s intensity table from a TM-33-18, TM-33-23 or UNI 11733 document, emitters on one grid summed, drawn as a 3D photometric web coloured by intensity, with the C0-C180 and C90-C270 polar curves and the luminaire outline from the dimensions the file states. Radiant and photon tables are drawn the same way.
The target: Stereolithography (.stl)
The universal 3-D printing mesh. Every slicer and every printing service takes it.
Opens in: Cura, PrusaSlicer, Bambu Studio, Meshmixer, any printing service.
Your file never leaves your computer
Both the TM-33 parser and the STL writer are JavaScript and WebAssembly running in your own browser tab. There is no upload step, no server-side conversion queue, and no copy of your file anywhere but your machine. That matters for drawings under NDA, for client work, and for anything you would not email to a stranger.
Free to Use, No Signup
There are no accounts and no watermarks on this converter. If it saved you time, the one thing we ask is a mention: a post, a link from your blog or course page, or a reply to someone asking how to open a file.
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Hear about new formats
Occasional emails when the viewer learns a new format or gets a new tool.
Frequently asked questions
▶Is this TM-33 to STL converter free?
Yes. No signup, no watermark, no per-file limit and no paid tier. Innerscene.
▶Is my TM-33 file uploaded anywhere?
No. The file is read with the browser file API and converted in the same tab. Nothing is sent to a server unless you explicitly click Share, which is a separate, opt-in feature.
▶Will my colors and materials survive the STL export?
STL has no concept of color or materials, so the per-vertex color in your TM-33 file are not written. The geometry is unaffected.
▶Do layers and named parts carry into the STL file?
STL is a single flat body with no layers or named parts. Everything merges into one object. If you need the structure, export to GLB, OBJ, DXF instead.
▶Will the STL open at the right size?
STL stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks.
▶How large a TM-33 file can I convert?
Up to 200 MB, and the ceiling adapts to how much memory your device reports. The conversion runs on your own hardware, so a desktop with plenty of RAM will handle more than a phone.
▶Can I convert STL back to TM-33?
Not here. We read TM-33 and write STL, but not the reverse. the universal 3D viewer
▶Which browsers does it work in?
Chrome, Edge, Firefox and Safari, on Windows, macOS, Linux, iOS and Android. No plugin and no extension.
Convert TM-33 to something else
Convert something else to STL
Or start from the universal 3D viewer.