SVG Stroke to Filled Outline Converter

Parametric Centerlines

Standard stroked paths contain only singular 1-dimensional coordinate sequences. The browser graphics pipeline computes the visual boundary on the fly by extruding pixels perpendicular to each instantaneous tangent vector.

Resolution Independence

When a stroked SVG is rendered at tiny icon dimensions (e.g., 16px) or scaled up to billboard proportions without strict viewBox scaling rules, strokes often blow out or collapse into invisibility.

Dual-Contour Enclosures

Stroke polygonization evaluates two parallel curves offset by $\pm \frac{w}{2}$ across the entire length of the path. Joining these contours into a single <path> with an evenodd fill-rule guarantees exact 1:1 visual fidelity across all renderers.

Engineering Best Practices

• • Tune Sampling Precision to Curve Complexity: Use sampling densities between 16 and 24 for standard iconography to keep file sizes low while avoiding visible facet edges on curved arcs.
• • Enforce `fill-rule="evenodd"`: When expanding closed geometries like circles or squares, ensure compound holes render transparently by preserving the evenodd rule.
• • Cleanse Deprecated Stroke Styling: Always strip obsolete stroke, stroke-width, and stroke-linecap attributes so downstream build minifiers (e.g., SVGO) can optimize payload sizes effectively.

Common Hazards to Avoid

• • Losing Interactive Stroke Animations: Do not convert icons designed for CSS stroke-dasharray reveal animations; outline conversion replaces single path spines with closed 2D loops.
• • Over-sampling Simple Linear Vectors: Avoid using maximum subdivision rates (e.g., 64 points) on straight lines or polygons, as this adds unnecessary coordinate bulk without visual benefit.
• • Missing Nested Transformations: Keep parent <g transform="..."> groups intact during export to prevent child paths from drifting out of alignment.