Simplify STL and 3MF models
Open a model with more triangles than any printer can show: a scan, a sculpt, a model from an AI generator. Flat and gently curved areas are rebuilt from fewer triangles on this device - the file is never uploaded - and painted colours stay where they were.
Pick a plate to simplify
Drop your model hereOpen your model
STL, OBJ or 3MF. It is read on this device and never uploaded.
A few hundred thousand triangles take ten seconds or so.
What it does
- Fewer triangles Flat and gently curved areas are rebuilt from fewer, larger ones.
- Detail kept No point of the surface moves further than the distance you allow.
- Colours kept Painted areas keep their colours, and their borders stay where they were.
- Ready to print The copy is watertight, repaired first if it needed it.
No point of the surface moves further than this. A nozzle lays lines 0.4 mm wide, so 0.1 mm does not show in a print.
Look at the copy in your slicer before you print it: it is lighter, and the slicer has the last word.
When a model is too heavy for the slicer
A mug from an AI generator comes with almost 300,000 triangles. The slicer opens it slowly, painting it is sluggish, and most of those triangles describe a surface flatter than a layer line. This tool keeps the shape and drops the excess, in three steps:
- Open the STL or 3MF above, or drop it onto the box. It stays on your device.
- Read the result and switch to Mesh to see the triangles that are left. Move the slider or the distance and press Simplify to try again.
- Save the copy as 3MF to keep the paint, or as STL, and load it in your slicer in place of the original.
Why painted models stop sooner
A colour painted with a brush in Bambu Studio or OrcaSlicer is stored inside the triangle it was painted on. Those triangles are kept exactly as they were, so the paint cannot shift: a model painted in fine strokes keeps more triangles than one painted in whole areas. The result says how many were kept for this reason.
The original file is never changed: the copy is saved beside it under its own name, ending in -simplified.
What the simplification does
Fewer triangles
Two triangles that lie in one plane say no more than one, and a gentle curve needs far fewer than a scanner or a generator writes. Edges are merged one at a time, cheapest first: the one whose removal moves the surface least goes before any that would change the shape.
The distance you allow
Every merge is checked against the original surface before it is made. If any point of the new surface would sit further from the original than the distance chosen, or any point of the original further from the new one, that merge is not made. The slider says how far to go; the distance says where to stop.
Colours
A 3MF painted in Bambu Studio or OrcaSlicer keeps its colours. Where two colours meet, the border is a line that stays a line: points on it move only along it. A triangle painted in brush strokes carries its strokes inside it, so it is kept exactly, with its paint.
Repaired first
The model goes through the same repair as the STL repair page before it is simplified: holes closed, flipped triangles turned out. A simplification never opens a hole or turns a triangle over, so the copy is watertight when the original could be repaired.
Projects and plates
An STL or OBJ is simplified whole. A Bambu Studio or OrcaSlicer project is simplified one plate at a time, each object on its own, so two parts that touch keep their own surfaces; every copy of an object on the plate gets the same simplified mesh.
What it does not do
It does not smooth, thicken or reshape the model, and it does not remesh it into even triangles: what is left are triangles of the original surface, larger where the surface is flat. Thin details narrower than the distance allowed may lose a little of their edge.
Questions people ask
Is my file uploaded?
No. The page loads the simplification into your browser, and the model is read, simplified and saved on your own device. Nothing about it is sent to us or to anybody else.
Does it keep the colours of a painted 3MF?
Yes. A Bambu Studio or OrcaSlicer project is saved back as that project, with its plates, settings and paint. Areas painted whole keep their colour and their borders, and triangles painted in brush strokes are kept exactly as they were.
Why did it keep more triangles than I asked for?
Because going further would have moved the surface more than the distance chosen, or because the triangles left are painted with a brush and are kept for their paint. The result says which. Allow a larger distance to go further; painted strokes stay either way.
What distance should I choose?
0.1 mm is finer than a 0.4 mm nozzle draws, so it does not show in an FDM print. For resin, or a model you will scale up, choose 0.03 or 0.01 mm. A larger distance removes more triangles and starts to soften fine detail.
Which files does it open?
STL (binary or ASCII), OBJ and 3MF. A project of several plates is simplified one plate at a time, and the project you save keeps every plate.
Is it free?
Yes, with no sign-up and no limit on how many files you simplify.
Will the copy print the same?
Within the distance chosen it is the same shape, and the slicer sees a watertight model. Look at it in your slicer before you print it. The tool is free and provided as is, without any warranty: we are not responsible for prints, material or time lost on a file simplified here.
From a lighter file to a priced order
The simplification stays free, with no account. If you sell what you print, LayerFlow3D reads the grams and hours your slicer works out for this copy and prices every order for it from them.