Convert FBX to STL
FBX is a game and film format. STL is what a slicer wants. Most of the work in going between them is not the triangles, it is the scale, the orientation and finding out whether the model is actually printable.
Drag a 3D file here, or.
This page is set up for FBX files. Other formats we can read work here too.
The file is read on your own computer. It is never uploaded.
Your file is read by your own browser and never sent to a server. There is no upload, no account and no copy of your model anywhere but on your computer.
Scale is the thing that goes wrong
FBX files are normally in centimetres and slicers read STL as millimetres. Send the numbers straight across and a character that should be 180 cm tall arrives 180 mm tall, or a prop meant to fit in your hand turns up the size of a room. The first unit box starts at centimetres for exactly this reason.
The measurements beside the 3D view are in the output unit, so you can check before downloading. If the height says 1800 and you expected a 180 mm figure, the source unit is wrong, not the model.
Game models are not print models
A mesh built for a game engine is usually a shell. It can have holes where the camera never looks, faces that are only one triangle thick, and pieces that overlap rather than join. None of that matters on screen and all of it matters to a slicer.
The panel under the 3D view says whether the result is closed, how many open edges it has, how many separate pieces there are and whether any surfaces meet in a way no solid object could. Finding that out here is a great deal better than finding it out forty minutes into a print.
Up axis
FBX is usually Y-up, which is how games and film work. Slicers and CAD are Z-up. Set the output up axis to Z and the model stands up on the plate instead of lying on its face.
The coloured marker in the corner of the 3D view shows which axis will be up in the file that gets written, so you can see the change take effect.
Subdivision and smoothing groups are not what you see in the viewport
A model built in Maya or 3ds Max is often shown in the viewport with subdivision previewed: a low-polygon cage displayed as the smooth surface it would become. What gets written to the FBX is usually the cage, not the smooth result, so a character that looked rounded on the artist’s screen arrives here visibly faceted.
Nothing here is broken when that happens, and no converter can fix it — the smooth surface was never in the file. It has to be applied before export, in the program that made it. In Maya that is Modify, Convert, Smooth Mesh Preview to Polygons; in 3ds Max it is collapsing the TurboSmooth modifier; in Blender it is applying the Subdivision Surface modifier.
This matters more for printing than for anything else, because a printer reproduces exactly the faceting in the file. The 3D view on this page shows the real geometry, without any smoothing preview, so what you see here is what the slicer will get.
What survives, and what does not
Kept in the STL file
- The exact shape of every mesh in the scene, assembled as the scene had it
- The real size, once you set the source unit correctly
- Correct outward-facing triangles, checked and repaired
Lost on the way
- Animation, skeletons and skinning weights
- Materials, colours and textures — STL stores none
- Object names: STL has one unnamed body
How to convert FBX to STL
Drop the .fbx file in
The whole scene tree is walked and every mesh is placed where the scene put it, so the model arrives assembled rather than in pieces at the origin.
Set the input unit to centimetres
This is the default and it is right for most FBX files. A 180 cm character arriving as 180 mm is this setting, not a broken file.
Set the output up axis to Z
FBX is Y-up because games and film are. Slicers are Z-up. Without this the model lies on its face on the build plate.
Read the closed-model check carefully
Game meshes are often shells with holes the camera never saw. The open-edge count and the separate-piece count are both beside the 3D view, and both matter more here than in any other FBX conversion.
Download the binary STL
Materials, textures, rigs and animation are all gone at this point. That is what an STL is, and the shape is what a printer needs.
FBX and STL compared
| Property | FBX.fbx | STL.stl |
|---|---|---|
| File contents | Binary in every version since 2009, with an older text form still accepted. | Binary or plain text. Binary is an 80-byte header, a triangle count, then 50 bytes per triangle. |
| Geometry | Triangles and polygons, with full skinning, blend shapes and animation curves. | Triangles only. Curves are approximated when the file is made, and cannot be recovered. |
| Units | Recorded in the file header, commonly centimetres. | None. The file stores bare numbers, and every reader has to guess what they mean. |
| Colour and texture | Materials and textures, optionally embedded inside the file itself. | None. There is no place in the format for a colour, a material or a texture. |
| Separate objects | A full scene graph with bones, cameras, lights and animation takes. | One body. Several parts written into one STL become one undivided lump of triangles. |
| Published by | Kaydara, 1996, bought by Autodesk in 2006. The format is closed. | 3D Systems, 1987, for the first stereolithography machines. |
| Written by | Maya, 3ds Max, MotionBuilder, Unity and Unreal. | Every CAD program and every slicer, as the common denominator. |
Questions
- My model came out far too big in the slicer. What do I fix?
- The first unit box. FBX is normally in centimetres; if your file was exported in metres or inches, say so there and the size is corrected before the STL is written.
- The panel says the model has open edges. Can I still print it?
- Sometimes. Slicers will try to close small holes on their own and often succeed. A large number of open edges usually means the model was built as a shell for a game and needs real work in a modelling program before it can be printed.
- Will the pose or animation come through?
- No. What you get is the geometry in the pose the file stores as its rest position. Animation cannot go into an STL, and neither can a skeleton.
- Binary or ASCII STL?
- Binary. It is about five times smaller and every slicer reads it. ASCII is a text file, occasionally asked for by older machines and always much larger.
- My model looks faceted, but it was smooth in Maya. Why?
- Because the FBX holds the subdivision cage, not the smoothed surface. Apply the smoothing before exporting — Modify, Convert, Smooth Mesh Preview to Polygons in Maya — and export again.
Having it printed
If the part is larger than your bed, needs a material your printer cannot handle, or you do not have a printer, these will print it and post it to you. Work out what it would cost you first — the cost calculator on this site gives you a figure to compare against.
- JLC3DPCheapest for resin and nylon, slow shipping
- CraftcloudCompares dozens of printers at once, including local ones
- PCBWayMetal printing and CNC as well as plastic
These are ordinary links, not paid referrals — we earn nothing if you use them. The converter above is the same whether you do or not.
Where to go next
Other things to do with a FBX file
Other ways to get a STL file
Related guides and tools
- Gridfinity generatorBins and baseplates, any size, built in the browser
- Turn text into an STLType a word and print it, without drawing anything
- Turn an image into an STLA photo or a logo, turned into something you can print
- Lithophane generatorA photo printed as thickness, lit from behind
- Repair an STL that will not sliceClose the holes and separate the bad edges so a slicer accepts it
- Convert BLEND to FBXGuide
- Convert GLB to FBXGuide
- STL to G-codeGuide
- How to convert an STL file to G-codeGuide