Preflight Check

Review SVG glyphs before export with red, yellow, and green status feedback.

Preflight Check helps catch problems that can make generated fonts unstable, hard to map, or visually misaligned.

What it checks

• Unicode conflicts.
• Duplicate glyph names.
• Empty SVG files.
• SVGs with no visible fill or stroke outlines.
• Abnormal SVG canvas size.
• Missing viewBox.
• Artwork outside the SVG canvas.
• Artwork outside expected baseline, ascender, or descender bounds.
• Unsupported SVG elements and attributes.
• External SVG resources.
• Glyph complexity limits.

Status colors

• Green: ready.
• Yellow: warning. Review before export.
• Red: error. The glyph is likely invalid or unsupported.

Build behavior

Preflight is a review step, not an unconditional blocker.

When issues are found, you can build only passing glyphs or continue with all glyphs and let the native build engine try them. The build engine may still reject unsupported or unsafe input during export.

Common fixes

• Convert live SVG text to outlines.
• Remove raster images from the SVG.
• Flatten clipping paths, masks, filters, and opacity effects.
• Add a stable viewBox.
• Keep artwork inside the canvas.
• Use unique glyph names.
• Assign unique Unicode values unless you are intentionally replacing a source font glyph.
• Simplify extremely detailed paths.

Icon font note

Icon fonts often use artwork that sits differently from text glyphs. Baseline or descender warnings can be intentional, but they are still useful because inconsistent alignment is one of the easiest ways to produce a messy icon font.