Free STL Viewer
Inspect STL geometry locally before slicing, 3D printing, conversion, or model handoff.
Inspect STL geometry locally before slicing, printing, or conversion.
About this tool: Free STL Viewer
Inspect STL geometry locally before 3D printing, slicing, conversion, or model handoff. No upload required — everything runs locally in your browser for privacy and speed.
Common use cases
- STL keeps geometry only, so do not expect color, texture, or PBR material preview.
- Use STL viewing as a quick geometry check before slicer import.
What an STL viewer is for
An STL viewer answers one question quickly: does this file look like the part, before it goes to the slicer. STL stores neither unit nor material, so the viewer shows shape only — the millimetre figure that decides scale is read in the slicer.
A ten-second check that saves a print
- 1
Confirm the size in the slicer
The viewer shows shape; the slicer shows millimetres. Compare the longest edge there against the real object — a factor of a thousand is a metres-versus-millimetres export, not a broken model.
- 2
Orbit to the underside
Open shells and floating faces hide behind a good camera angle. The bottom is where a bad export admits itself.
- 3
Look at the thinnest wall
Compare the narrowest feature with your nozzle diameter and layer height before committing filament to it.
STL viewer questions
- Can I view an STL without uploading it?
- Yes. The viewer parses the file in your browser, so the model stays on your machine.
- Why is my STL grey?
- Because STL has no colour or material to show. Grey is the format, not a setting.
- Can the viewer show textures?
- Not for STL. If the model needs to look right rather than just measure right, open the GLB in the GLB inspector instead.
Quick tips
- STL keeps geometry only, so do not expect color, texture, or PBR material preview.
- Use STL viewing as a quick geometry check before slicer import.
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