Repair an STL Online,
Free & In Your Browser
Drop in a broken STL and MeshTune fixes the open holes, non-manifold edges and self-intersections that stop it printing — repairing it to a watertight, manifold solid you can download in seconds. No upload, no install, no account.
Nothing is uploaded. Repairs run inside your browser, not on a server — no account, no limits. Your STL only ever leaves your machine if you deliberately attach it to a bug report.
How to Repair an STL for 3D Printing
Three steps, all in the browser. There is nothing to install and nothing to upload — the whole repair runs on your own machine.
Open Your STL
Drag your STL into the viewer. It is read straight from your disk — no upload, no waiting on a server.
Analyze & Repair
Run Analysis to see what's wrong, then click Repair — holes filled, duplicates welded, non-manifold edges split, winding fixed.
Download the Fixed STL
Confirm the printable verdict — closed, manifold, oriented — and download the repaired STL, ready to slice.
Every Defect That Stops an STL From Printing
A slicer needs a single, closed, solid shell. MeshTune finds and repairs the eight problems that break that assumption — the same ones a print will fail on.
Open Holes
Gaps in the surface leave the model non-watertight. Repair fills every boundary loop so the shell is closed — see make an STL watertight.
Non-Manifold Edges
Edges shared by three or more faces confuse slicers. Repair splits them into clean, separate sheets.
Self-Intersections
Triangles that pass through each other create ambiguous solids. They're detected with an exact geometry test.
Flipped Faces
Inconsistent winding makes normals point the wrong way. Repair re-orients every face outward.
Duplicate & Degenerate
Coincident vertices and zero-area triangles are welded away, cleaning up the mesh before it's rebuilt.
Stray Shells
Loose islands and scan debris are removed, so what's left is the single solid body you meant to print.
A Free Netfabb & Meshmixer Alternative
Netfabb is a paid Autodesk product; Meshmixer is no longer actively developed; and most browser-based repair services upload your model to their servers. MeshTune is free, current, and private by design.
| MeshTune | Netfabb | Meshmixer | Upload-based sites | |
|---|---|---|---|---|
| Price | Free | Paid subscription | Free (legacy) | Free / paid tiers |
| Files stay private | Yes — nothing uploaded | Yes (desktop) | Yes (desktop) | No — uploaded to a server |
| Install required | None — runs in browser | Desktop install | Desktop install | None |
| Actively maintained | Yes | Yes | Discontinued | Varies |
| Watertight repair | Yes | Yes | Yes | Varies |
Comparison of common STL-repair options. Product names are trademarks of their respective owners; details may change over time.
Your STL Never Leaves Your Machine
MeshTune loads and repairs your file entirely in the browser tab — Three.js for rendering and a WebAssembly mesh engine for the repair. No servers, no uploads, no accounts. For proprietary parts, patient scans and client work, the file simply never travels. Refresh the page and it's gone.
STL Repair — Common Questions
Is STL repair on MeshTune free?
Yes — completely free, with no sign-up, no subscription and no file-size limit. Every check and repair runs in your browser.
Does MeshTune upload my STL file?
No. Your file is read directly from your disk and repaired locally using a WebAssembly mesh engine. Nothing is ever sent to a server, and refreshing the page clears it from memory.
What does the repair actually fix?
It fills open holes, welds duplicate vertices, drops degenerate and duplicate faces, splits non-manifold edges, fixes flipped faces and re-orients the surface outward — producing a watertight, manifold, printable STL. A verdict confirms the result is closed, manifold and oriented before you download.
What is a non-manifold edge, and why does it break a print?
A non-manifold edge is one shared by more than two faces. Slicers such as Cura and PrusaSlicer treat a mesh as a single solid shell, so a non-manifold edge breaks that model and produces failed or malformed prints. MeshTune highlights these edges and splits them apart during repair.
Is this a free alternative to Netfabb or Meshmixer?
Yes. Autodesk Netfabb is a paid product and Meshmixer is no longer actively developed. MeshTune is a free, in-browser alternative for checking and repairing STL files — and unlike upload-based online services, it never sends your model to a server.
Can I repair OBJ, PLY or STEP files too?
Yes. MeshTune loads STL, OBJ, PLY, STEP and IGES, repairs the mesh, and exports the result back out as STL, OBJ or PLY.
Repair Your STL Now — Free
Drop a file into the viewer and have a watertight, printable STL in under a minute. Nothing uploaded, nothing installed.