What is an STL viewer?
STL is the standard file format for 3D printing and rapid prototyping. An online STL
viewer lets you open and inspect .stl files without installing CAD
software — useful for a quick check before slicing, sharing a model with a client,
or verifying an export. This viewer runs entirely in your browser: both binary and
ASCII STL files are supported, on desktop and mobile.
Features
- Instant 3D preview — orbit, zoom and pan with mouse or touch.
- Wireframe & auto-rotate toggles for inspecting mesh quality.
- Model stats — file size, triangle and vertex counts at a glance.
- Private — files are parsed locally; nothing is uploaded.
Need to convert a CAD file to STL first?
If your model is in STEP or IGES format, convert it first with our free STEP to STL converter or IGES to STL converter — then preview the resulting STL right here.
FAQ
- Is this STL viewer free?
- Yes — free forever, no account, no limits.
- Are my STL files uploaded to a server?
- No. Files are read and rendered locally in your browser via WebGL. They never leave your device.
- Does it work on mobile?
- Yes — touch controls (one finger to rotate, pinch to zoom) work on phones and tablets.
- What is the maximum file size?
- There is no artificial limit, but very large models (hundreds of MB) may be slow depending on your device's memory.