Check Mesh is an overlay tool that highlights topological characteristics and potential issues in real-time while modeling. It identifies N-gons, triangles, non-manifold geometry, complex poles (including bowties, N-poles, and E-poles), non-flat faces, and intersecting or overlapping meshes. The tool integrates directly into Blender's Overlays menu, functioning across edit mode, sculpt mode, and retopology workflows. Users can customize the highlight colors to contrast with their active theme or MatCaps. It also includes selection operators in edit mode for each component type and provides a mesh sorting list based on polygon count.