Current app

STLa

STLa helps you open STL files, check mesh problems, and repair damaged geometry on your Mac. It works best when a model is mostly intact but has local issues that make slicing, validation, or printing unreliable. The app saves a repaired STL plus a readable JSON report, and it is planned as a simple single-purchase app that works offline for normal use.

macOS Works offline Single purchase planned App Store link coming later

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Use case

What STLa is for

STLa is built for people who need to inspect and repair STL files before printing, sharing, or reuse. It focuses on practical mesh repair rather than full part reconstruction.

Open triangulated STL files on your Mac.
Inspect for holes, open edges, non-manifold geometry, flipped faces, and similar mesh problems.
Repair the structural issues STLa can repair safely, with progress feedback along the way.
Save a repaired STL and a readable JSON report showing what changed.

Version 1

Current product approach

The current version is designed to protect privacy while keeping the workflow straightforward.

STLa does not collect personal data.
Planned as a single-purchase app.
No subscription and no hidden paid unlocks.
No account is required.
No third-party analytics are planned for version 1.
Files are chosen by the user and handled locally on the Mac.
Core workflows are designed to work without an internet connection.
Basic shape creation is available as a secondary workflow.

Repair guidance

How STLa fits real-world mesh repair work

STLa is meant to solve many common STL repair problems while staying honest about where automatic repair stops being reliable.

What STLa repairs

Problems it is especially good at handling

STLa performs best on structural mesh problems that are clear, local, and repairable without guessing too much about the intended shape.

Open edges and simple holes in an otherwise solid mesh.
Small missing caps, punctures, and seams where triangles are absent.
Face-direction mismatches where some triangles point inward and others outward.
Duplicate faces and opposite-facing duplicate faces.
Degenerate triangles, including zero-area or nearly collapsed triangles.
Some non-manifold edges or vertices when cleaner local shells can be separated without heavy guesswork.

Best for

When STLa usually performs best

You should expect the strongest results when the model still mostly represents the intended part and the damage is limited.

The model is mostly intact and still looks like the part it is supposed to be.
The damage is local rather than spread across the whole object.
Missing geometry is small compared with the overall mesh.
The mesh is close to watertight, but has a manageable number of defects.
You need mesh repair, not a full redesign or recreation of the part.

Limits and expectations

What STLa is not trying to do

STLa is not a full CAD reconstruction tool. It repairs mesh structure, but it does not understand design intent the way a parametric CAD model does.

A successful repair does not always mean a perfect repair.
Sometimes a mesh becomes printable, but small geometric differences remain.
If STLa reports a deviation warning, the structure was repaired but the result should be reviewed carefully.
Large missing sections, severe scan noise, or contradictory geometry can leave too much ambiguity for automatic repair.
If a part needs sharp-feature recreation, dimension-critical rebuilding, or manual remodeling, STLa is not the right final tool for that job.

Too damaged for automatic repair

When another workflow is usually the better next step

Some meshes are simply too far gone for reliable automatic repair, even when they still open as STL files.

Models with major chunks missing.
Meshes with severe self-intersections or heavy internal overlaps.
Nested or tangled shells that need advanced volumetric or manual cleanup.
Very thin, messy, or conflicting surfaces where it is unclear what should be kept.
Files that technically contain triangles but represent the wrong shape because the source export was badly corrupted.
Parts that need engineering judgment to decide which surfaces are intentional and which are accidental.

STLa is a practical repair tool for many real-world STL problems when the model is still mostly there. It is not meant to recreate severely damaged geometry from nothing, but it can save time on many mesh issues that would otherwise block slicing, validation, or printing. When a mesh is too damaged for a trustworthy automatic result, the professional next step is usually manual remodeling or returning to the original CAD or scan source.

Support details

What to include if you need help

The STLa version and your macOS version.
What you expected to happen.
What actually happened.
Whether you used a fast, balanced, or more thorough repair path.
If the issue is a failed repair, use the support form and attach the JSON repair report.

Public resources

Ready for App Store linking

This page is ready to sit alongside the public support and privacy pages as the release gets closer.

Support STLa privacy