1 stroke · 20px · round · bare
Hairline icons
Whisper-thin 1px strokes with no frames: quiet, precise and expensive-looking.
Nothing gives away a generated UI faster than icons at four stroke widths and three sizes. An icon style fixes the stroke, the size, the line ends and how standalone icons are framed. Once it's in your sheet, your agent draws every icon the same way and check_ui flags the ones that drift.
10 styles · Lucide (lucide-react) · apply to your sheet in one click
1 stroke · 20px · round · bare
Whisper-thin 1px strokes with no frames: quiet, precise and expensive-looking.
1.5 stroke · 20px · round · bare
Balanced 1.5 strokes with no frames, the safe and readable default for product UI.
2.25 stroke · 20px · round · bare
Heavy rounded strokes that hold their own next to bold type and stay friendly and legible at small sizes.
2 stroke · 20px · square · bare
Square line ends and mitred corners for a technical, blunt, graphic look.
1.75 stroke · 20px · round · soft
Icons in accent-tinted rounded tiles: the friendly SaaS feature-list look.
1.5 stroke · 18px · round · outlined
Hairline-bordered tiles with text-coloured icons that feel calm, structured and neutral.
2 stroke · 18px · round · solid
Icons knocked out of solid accent tiles, with confident app-icon energy for features and settings.
1.75 stroke · 18px · round · circles
Icons centred in soft tinted circles, gentle and approachable for health, finance and onboarding.
2.5 stroke · 20px · square · solid
Chunky square-ended strokes on solid accent blocks: loud, graphic and unmistakable.
1.25 stroke · 22px · round · outlined
Fine strokes at a slightly larger size in outlined tiles for a refined, airy, print-like feel.
With your agent
Lucide, through lucide-react. It's open source (ISC licence), tree-shakeable and already in most React and shadcn projects. Each style is a stroke width, size and frame, so there's nothing new to install.
Your sheet's CLAUDE.md gives the exact strokeWidth and size (or a LucideProvider to set them once), and check_ui warns about icons from other libraries or at a different stroke.
More of the library
Guides and articles
Save what you love to a sheet, connect Claude or Cursor, and every screen comes out in your style. Free for 3 days on annual plans, card needed.