Design & web tools.
Nothing leaves this page.
100% client-side · 0 trackers · 0 cookies · verify in DevTools → Network
HEX ⇄ RGB ⇄ HSL ⇄ HSV with a WCAG contrast check.
Linear & radial gradients with a live preview and copyable CSS.
Generate SEO + social tags with Google and card previews.
Letter or emoji on a shape → PNGs at 16–512px.
Any text or URL → crisp QR, exportable as SVG or PNG.
Percent-encode, decode and break a URL into its parts.
Placeholder text by words, sentences or paragraphs.
Why ui0?
Most online design utilities — color converters, gradient makers, favicon and QR generators — are ad-heavy pages that may track what you paste and what you build. ui0 runs every tool in your browser: colors, gradients, favicons, QR codes and meta tags are all generated client-side, with no accounts and no uploads. Open DevTools → Network and you'll see zero outbound requests while you work. One real URL per tool, easy to bookmark and share.