A free, private, browser-based STL and 3MF splitter for oversized 3D-print models. Orient a model, cut it repeatedly, check every resulting part against your printer build volume and safety margin, then export slicer-ready STL or 3MF files. No upload, account, CAD installation, or server-side model processing is required for the core tool.

Hi Product Hunt! We built PartFit 3D for a problem that shows up constantly in 3D printing: finding a great model, then realizing it is larger than the printer's build volume. The usual options often mean opening a full slicer or CAD package before you can even answer the basic question: will every piece actually fit? PartFit puts that fit check at the center of the workflow. You can orient an STL or 3MF model, choose a printer, add a safety margin, make repeated cuts, and see a Fit or Too Large result for every part. When everything fits, export the set as STL files or one 3MF project and finish the job in your slicer. Privacy was equally important to us. Model geometry stays in the browser by default, so the core tool does not require an account or upload your design to our servers. We would love feedback from makers: which printer profiles or splitting workflows should we improve next?

Split a model in my browser without uploading anything feels great, especially for large files I wouldn't trust to random servers. Really like that it flags which chunks won't fit my build plate before I bother exporting.

@glerdagu Thanks so much! Privacy and fit checking are exactly what we built PartFit around, so it’s great to hear they’re useful to you. If you have a moment, I’d love to hear what felt confusing, inconvenient, or missing while you were splitting your model. Any honest feedback would really help us improve it!

PartFit 3D

Split STL & 3MF files to fit any 3D printer

Split STL & 3MF files to fit any 3D printer