A Free Netfabb Alternative for STL Repair
Netfabb is aimed at production additive manufacturing, and it is priced accordingly. Most people searching for an alternative don't need build preparation or lattice generation — they need one broken file to become printable.
Drop your STL file here
or
Nothing is uploaded — the repair runs on your own machine.
The gap Netfabb leaves for hobbyists
Netfabb — now sold as Autodesk Fusion with Netfabb — is a serious piece of engineering software: build packing, lattice structures, simulation, machine-specific preparation. If your job involves running an industrial printer, that capability is what you are paying for. If your job is a single downloaded model that won't slice, most of it sits unused.
There is a 30-day trial, and students and educators can get a year free through Autodesk's education plan. Outside of those, it is a paid subscription — a lot of commitment for a capability you might need twice a month.
What you get here, for nothing
The repair pipeline handles the defects that stop a slicer: open boundary loops are closed, non-manifold edges and pinched vertices are separated into clean topology, inverted faces are re-oriented outward, zero-area and duplicate triangles are stripped out, and self-intersecting shells are merged with a boolean union so the result is a single valid solid.
It runs entirely in your browser. No install, no licence, no account, and the model is never transmitted anywhere — it is processed on your own CPU by a WebAssembly build of an open-source geometry engine.
An honest report instead of a silent fix
Professional tools give you detailed diagnostics because professionals need to justify what changed. Free online tools almost never do — they hand back a file and leave you to hope.
This one prints the repair log in plain language: holes sealed, faces re-oriented, junk triangles removed, whether the result is watertight, how many separate shells it contains, and how confident the engine is. When the model is large enough that the self-intersection check is skipped for speed, it tells you the check did not run rather than showing a reassuring green tick. You can copy that report as text and paste it into a forum thread when you ask for help.
Side by side
| This tool | Netfabb | |
|---|---|---|
| Price | Free | Paid subscription; 30-day trial, free for education |
| Install | None — browser only | Desktop install and licence |
| Mesh repair | Automatic, one click | Automatic and manual, very thorough |
| Repair report | Plain-English, copyable | Detailed technical diagnostics |
| Build preparation, packing, lattices | No | Yes |
| Industrial machine profiles | No | Yes |
| Very large production files | Limited by browser memory | Designed for it |
Pricing and edition details were checked in August 2026 and are the ones Autodesk publishes; they change from time to time. Check Autodesk's own pages for current terms before you decide.
When Netfabb is worth it
If you are preparing builds for an industrial machine, packing many parts into one build volume, generating lattice structures, or need repair you can document and defend for a client, Netfabb is the right tool and this is not a substitute. Production work needs software with support behind it.
For a hobbyist or a small shop fixing downloaded and scanned models, the honest answer is that you are unlikely to touch the features you would be paying for.
Try it on the file that's giving you trouble. You'll see the triangle count and a time estimate before anything runs, so there's no waiting on a spinner to find out.
Open the full repair toolFrequently asked questions
Is there a free version of Netfabb?
Not for general commercial use. It is sold as Autodesk Fusion with Netfabb, with a 30-day free trial. Students and educators can get free access for a year through Autodesk's education plan. For everyone else it is a paid subscription, which is why people who only need occasional mesh repair often look for something lighter.
Can this handle the same repairs as Netfabb's automatic repair?
For the common defects that stop a slice — holes, non-manifold edges, flipped normals, degenerate triangles, self-intersections — yes. Netfabb goes further with manual repair control and production build preparation, which this tool does not attempt.
Do I need to create an account?
No. There is no signup, no licence key and no usage limit. The site is supported by advertising.
Is it safe to use with client work?
The file never leaves your computer, so there is no confidentiality question about uploading. Whether the repaired result is suitable for a client job is your call — always inspect the model in your slicer before printing.