CHECK THE MESH. KNOW THE LIMITS.
Find mesh errors before your next print.
Local diagnostics. A report you can keep.
DIAGNOSTIC REPORT
Counts describe the stored triangles. Even a clean report needs a unit check and slicer review.
Your model stays in this browser. Start with either sample.
01 / READ THE REPORT
Open edges can indicate holes. Edges used more than twice, disconnected vertex fans and inconsistent adjacent winding need a closer look. Duplicate and zero-area triangles can also distort edge counts: remove those first, then check again.
Multiple vertex-connected components may be a valid assembly. We flag additional components for review rather than deleting them. STL has no standard unit field, so bounding dimensions are shown in raw coordinate units.
02 / HOW TO CHECK AN STL
CHECKING ≠ CERTIFICATION
No counted topology issues means these specific tests found no issue. It does not prove a model is watertight, outward-facing or suitable for your printer. Self-intersections and thin walls need other checks.
This tool reads geometry and does not repair or export an STL. Use the repair tool comparison to choose a suitable next workflow.
03 / FAQ
No. Parsing and diagnostics run in a worker in this browser. Report downloads contain your filename and counts, not the model geometry.
No. Non-manifold structures, self-intersections or overlapping solids can still exist. This checker does not certify watertightness or printability.
No units are assumed. STL has no standard units. Confirm whether the coordinates represent millimeters, inches or another unit in your slicer.
This page produces a diagnostic report. Use the STL fixer for simple repairs, or a desktop editor for complex topology. Choose the file again in the other tool.