Transitions.dev is an interactive collection of reusable CSS transitions. Each card on the index page demonstrates a different interaction pattern and ships a copy-ready, portable CSS snippet for each.
Live site: https://transitions.dev/
| # | Name | What it shows |
|---|---|---|
| 1 | Card resize | Smooth card resize transition. |
| 2 | Number pop-in | Digit flip with blur and stagger. |
| 3 | Notification badge | Diagonal slide with spring pop-in. |
| 4 | Text states swap | Text swap transition with blur. |
| 5 | Menu dropdown | Origin-aware open / close transition. |
| 6 | Modal open / close | Modal transition with scale. |
| 7 | Panel reveal | Panel open / close transition. |
| 8 | Page side-by-side | Forward / back page transition. |
| 9 | Icon swap | Scale and blur icon swap. |
| 10 | Success check | Confirmation icon with fade, rotate, blur, Y-bob, and SVG path draw. |
| 11 | Avatar group hover | Hovered avatar springs up while neighbours follow with a falloff. |
| 12 | Error state shake | Input shake on validation error with auto-revert to neutral. |
Each card has a copy button that emits a self-contained CSS snippet: semantic CSS custom properties on :root, the transition rules namespaced under t-* classes, and a @media (prefers-reduced-motion: reduce) guard — so you can paste the snippet into any project and apply it to any component without pulling in demo-specific markup or sizing.
The same twelve transitions are packaged as an installable agent skill so AI coding tools (Cursor, Claude Code, Codex, …) can apply them directly inside your project.
npx skills add Jakubantalik/transitions.devSkill source lives in skills/transitions-dev/ — SKILL.md, twelve per-transition reference files (01-card-resize.md … 12-error-state-shake.md), and _root.css (the universal install block on its own).
The skill is generated from index.html so the snippets always match what the showcase site demonstrates. Re-run after editing the source site:
npm run buildbuild/extract.mjs parses PROTO_TEMPLATES and the :root { --pX-* } block out of index.html, then re-renders every file under skills/transitions-dev/ from the templates in build/templates/.
index.html— main showcase page with all twelve transitions and per-card "copy CSS" buttons.prototypes.html— interactive playground for each transition with live tuning controls (durations, distances, easings).skill.html— landing page for the agent skill (install instructions + side-by-side compare embed).example.html— modal demo with a side-by-side "generic AI output" vs "with Transitions.dev skill" toggle, embedded insideskill.htmlas an iframe.skills/transitions-dev/— published skill payload (consumed bynpx skills add).build/extract.mjs+build/templates/— regenerator that keeps the skill in lockstep withindex.html.assets/— icons, favicons, and the social-share OG image.site.webmanifest,robots.txt,sitemap.xml— PWA/SEO metadata.
python3 -m http.server 8765Then open http://127.0.0.1:8765/.