No upload · No account · Up to 500 MB
Free STL repair
Fixes holes, flipped triangles, loose seams and inside-out parts, so your slicer stops complaining. It runs on your own computer: your file never leaves it.
The repair happens in this browser tab. Nothing is sent to Loftsmith or anyone else.
Questions
What does it fix?
Holes and gaps in the surface, triangles facing the wrong way (flipped normals), seams where corners almost meet, duplicate and collapsed triangles, parts that are inside out, and tiny loose specks. The result is a closed, watertight mesh that slicers accept.
Is my file uploaded?
No. The repair runs in your browser, on your own computer. The file never leaves it, so it's fine for customer files and work under NDA.
How big can the file be?
Up to 500 MB, about 10 million triangles, on a computer with 8 GB of memory or more. A 50 MB file usually takes a few seconds. Phones handle smaller files.
Does it change the shape?
No. It welds corners that should meet and closes holes with flat patches. Everything else stays exactly where it was. Overlapping bodies stay as separate bodies; slicers merge them when they slice.
Is it really free?
Yes, with no account and no limit on the number of files. It's made by Loftsmith, where you describe a part in a sentence and get a printable design for your printer.