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Edit an STL for 3D printing
Open an STL, OBJ, 3MF, STEP, GLB or PLY model and get it ready to print: repair holes and flipped triangles, fill hollow spaces sealed inside, cut it into parts with pegs that fit together, make the file smaller, combine or subtract models, mirror and scale, and see its size, volume and weight in plastic — then save STL, 3MF, OBJ or STEP. All of it runs in your browser.
No server processing
No account
No daily limits
Saves model files for your slicer, never printer code. Opened and sliced in PrusaSlicer, OrcaSlicer, Bambu Studio and Cura.
What it does
ReadsSTL (.stl) — binary or text, from any CAD program, Thingiverse, Printables or MakerWorld
OBJ (.obj) — from Blender, SketchUp, ZBrush or a 3D scan
3MF (.3mf) — from Bambu Studio, PrusaSlicer, OrcaSlicer, Cura or 3D Builder; every object in it opens as its own part
STEP (.step, .stp) and IGES — CAD drawings from Fusion, SolidWorks, Onshape, FreeCAD or Inventor; every body opens as its own part
glTF (.glb, .gltf) — from Blender, Sketchfab or an AI 3D generator; metres turned into millimetres, Y-up into Z-up
PLY (.ply) — from a 3D scanner, photogrammetry or MeshLab, text or binary
OBJ (.obj) — from Blender, SketchUp, ZBrush or a 3D scan
3MF (.3mf) — from Bambu Studio, PrusaSlicer, OrcaSlicer, Cura or 3D Builder; every object in it opens as its own part
STEP (.step, .stp) and IGES — CAD drawings from Fusion, SolidWorks, Onshape, FreeCAD or Inventor; every body opens as its own part
glTF (.glb, .gltf) — from Blender, Sketchfab or an AI 3D generator; metres turned into millimetres, Y-up into Z-up
PLY (.ply) — from a 3D scanner, photogrammetry or MeshLab, text or binary
Writes3MF (.3mf) — every part kept as its own object, exactly as on screen
STL (.stl) — binary, the file every slicer opens
OBJ (.obj) — for Blender and other 3D programs
STEP (.step) — a faceted solid for CAD: flat areas joined into single faces, so a box has six faces, not twelve triangles
STL (.stl) — binary, the file every slicer opens
OBJ (.obj) — for Blender and other 3D programs
STEP (.step) — a faceted solid for CAD: flat areas joined into single faces, so a box has six faces, not twelve triangles
Operationssee the model from any side, repair holes, flipped and broken triangles, fill closed hollow spaces inside, cut it in two along X, Y or Z or at any angle, pegs and holes, or separate pins, to join the parts, reduce the number of triangles, combine models into one, subtract one model from another, keep only where models overlap, split into separate parts, mirror, scale by percent or to an exact size, fix a model drawn in inches, move and turn by dragging arrows and rings or by exact numbers, add a box (also with rounded edges), cylinder, sphere, cone, pyramid or hexagon of a given size, a screw hole for M2–M8 or an M6–M30 thread — as a part or to cut a hole, lay it on the bed or on any flat face you click, size, volume, surface and weight in PLA, PETG, ABS and other plastics, keep the colours painted in Bambu Studio, OrcaSlicer or PrusaSlicer, and give each part its own colour, save several parts as one 3MF or as separate files
Fix a file
Repair an STLCut an STL into partsReduce STL file sizeMerge STL filesSubtract one STL from anotherFill a hollow STLSTL size, volume and weightMirror or scale an STLMeshmixer alternative3D Builder alternative
Open a file
Open an STL file — view, measure and fix itOpen an OBJ file and get it ready to printOpen a 3MF file
Conversions and clean-up
Why it gets the details right
Repair that keeps the shapeHoles are closed along their own edges and flipped triangles are turned, rather than rebuilding the model out of voxels — the surface stays where it was. Checked with PrusaSlicer on real broken models from Thingi10K.
Cuts that fit back togetherCut along any axis or at any angle and add round or square pegs — two or more, so the parts cannot twist — with a gap you choose for your printer. If the cut face is too narrow for the size you set, smaller pegs are used and you are told. Or holes in both parts and separate pins.
Solid geometry, not guessesCombine, subtract and cut run on Manifold, the open-source geometry library OpenSCAD and Blender use for the same job — the result is always a closed, printable solid.
Made for your slicer, not your printerIt saves model files, never printer code: temperatures, speeds and the G-code come from your own slicer and printer profile, and nothing here changes them. Saved files were opened and sliced in PrusaSlicer 2.9, OrcaSlicer 2.4, Bambu Studio 2.8 and Cura 5.13 — 3MF with painted colours, STL, OBJ and STEP (Cura reads no STEP on its own). As with any model, look at the slicer preview before you print.
Nothing to installWorks on Windows, Mac, Linux and a Chromebook, where Meshmixer and 3D Builder do not and where Bambu Studio cannot repair a model. The model never leaves your browser — nothing is uploaded.