STL viewer: open .stl files online
Drop a .stl file to view it in 3D right in your browser. No install, no sign-up, nothing is uploaded.
STL describes only the surface of a model as triangles — no colors, materials or textures. It is the default format for 3D printing and slicers.
More than a preview
24 formats in one window
GLB, glTF, FBX, OBJ, STL, PLY, DAE, 3MF, USDZ, 3DS, VOX, VRML, 3DM, AMF, LWO, KMZ, MD2, VTK, SVG, PCD, XYZ, BVH, G-code and PDB — plus .bin, .mtl and textures next to the model.
LODs and variants
Switch LOD0–LOD3, show one variant at a time or hide parts of the scene — handy for game assets with several levels of detail.
Real numbers
Triangles, vertices, meshes, materials, textures, bones and size in meters — check the budget before the asset goes into the engine.
Convert in one click
Save the visible model as GLB, OBJ, STL, PLY or USDZ. The conversion runs in your browser.
Private by design
Parsing and rendering happen on your device. The file is never sent to a server.
Free, no account
No limits on opening files, no watermark, works on desktop, tablet and phone.
What a STL file can hold
Stereolithography
- Geometry
- Yes
- Materials
- No
- Textures
- No
- Animation
- No
- Scene hierarchy
- No
- Typical use
- 3D printing, CAD
How to open a STL file
- 01
Drag the .stl file into the window or click “Choose files”. If the model uses separate textures, select them together with it.
- 02
Rotate with the left mouse button, zoom with the wheel, pan with the right button. On a phone use one and two fingers.
- 03
Check the stats, switch LODs or variants, then save a screenshot or convert the model to the format you need.
Why a STL file may not open
An empty or corrupted file, or an ASCII STL with a broken header. STL never has colors or textures — that is normal.
What to do next with a STL file
Convert it to GLB for engines and the web, reduce polygons, generate LODs or compress it — all free in the browser.
3D Model Converter
Convert FBX, OBJ, STL, GLB, DAE, 3MF, USDZ and more to GLB, glTF, OBJ, STL, PLY or USDZ.
OpenGLB / glTF Compressor
Shrink GLB files: Meshopt geometry, WebP or KTX2 (Basis) textures.
OpenPolygon Reducer
Reduce triangle count of any model while keeping its shape.
OpenLOD Generator
Generate LOD0–LOD4 from one model, named for Unity and Unreal.
OpenMore ways to inspect your model
Wireframe Viewer
See the polygon mesh of any 3D model, with wireframe over solid shading.
OpenUV Checker
Check UV unwrapping with a checker texture and see the UV layout.
OpenFlipped Normals Checker
Find flipped faces: back sides are painted red.
OpenPBR Channel Viewer
Look at base color, normals, roughness and metalness one channel at a time.
OpenLighting Preview
Preview a model under studio, sun, overcast, sunset and night light.
Open3D Model Measure Tool
Measure distances on a 3D model and compare it with a 1.8 m person.
OpenCompare 3D Models
Compare two 3D models or two LODs side by side with a slider.
OpenLOD Viewer
See LOD levels switch by distance, like in a game engine.
OpenTexture Inspector
List the textures in a model with size, slot and video memory.
OpenPolygon Counter
Count triangles and vertices of a 3D model, mesh by mesh.
OpenQuestions
Is the STL viewer free?+
Yes. Opening, inspecting and converting files is free, without an account or watermark.
Is my STL file uploaded anywhere?+
No. The file is read and rendered locally in your browser and never leaves your device.
Why does my STL model open without textures?+
The textures are probably stored as separate files. Select the model together with its texture images (and .bin or .mtl files) — the viewer links them by file name.
Can I convert STL to another format?+
Yes. After opening, use “Convert and download” to save the visible model as GLB, OBJ, STL, PLY or USDZ.