NexusLabs CSS Toolkit — 5 Design Tools

5 design utilities in one popup — pick colors, style backgrounds, and convert units without leaving your tab. Fully offline.

Stop switching between websites for everyday design tasks. NexusLabs CSS Toolkit puts 5 powerful, privacy-first styling utilities into a single beautiful popup — right in your browser toolbar. Whether you need to quickly translate a color between different formats, create a harmonious set of tones, design a smooth background transition, convert between sizing units, or fine-tune a depth effect — CSS Toolkit handles it in one click without leaving your current tab. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✅ What You Can Do Pick any color and instantly see its value in every common format — hex, RGB, and HSL. Adjust individual channels with sliders, preview the result in real time, and copy the output with one click. Need a coordinated set of tones? Enter a base color and generate complementary, analogous, triadic, tetradic, shade, and tint variations automatically. Each swatch shows its value and can be copied individually. Build smooth background transitions by choosing a direction, picking your starting and ending colors, and optionally adding a third stop. Preview the result live and copy the ready-to-use style rule. Convert between common sizing units — pixels, rems, ems, points, and percentages — with a configurable base size. Type a value in one field and see all conversions update instantly. Fine-tune depth effects with intuitive sliders for offset, blur, spread, and opacity. Toggle the inset option, pick a shadow color, and preview the result against a live element — then copy the finished style rule. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔒 Privacy First This extension makes zero network requests. Everything runs 100% locally in your browser. There are no analytics, no trackers, and no data is saved, cached, or persisted. It requests no special permissions and has zero access to your browsing history, tabs, or bookmarks. The full source code is available on GitHub. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎨 Designed for Daily Use The interface uses a modern dark theme with a clean tabbed layout. Switch between tools instantly, and everything works at any zoom level with smooth animations and visual feedback. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ NexusLabs CSS Toolkit is part of the NexusLabs extension family. Visit nexuslabs.website for 325+ free online tools.