@humanspeak/svelte-motion


Why are we here?

Motion vibes, Svelte runes. This brings Motion’s declarative animation goodness to Svelte with motion. components, interaction props, and composable config. If you spot a cool React example, drop it in an issue—we’ll port it. 😍

Requests welcome: Have a feature/prop/example you want? Please open an issue (ideally include a working Motion/React snippet or example link) and we’ll prioritize it.

Supported Elements

All standard HTML and SVG elements are supported as motion components (e.g., motion.div, motion.button, motion.svg, motion.circle). The full set is generated from canonical lists using html-tags, html-void-elements, and svg-tags, and exported from src/lib/html/.

- HTML components respect void elements for documentation and generation purposes.
- SVG components are treated as non-void.
- Dashed tag names are exported as PascalCase components (e.g., color-profile → ColorProfile).

Configuration

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This package includes support for MotionConfig, which allows you to set default motion settings for all child components. See the React - Motion Config for more details.

``svelte


Inherits 0.5s duration

`

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Svelte Motion supports minimal layout animations via FLIP using the layout prop:

`svelte

`

- layout: smoothly animates translation and scale between layout changes (size and position).
- layout="position": only animates translation (no scale).

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Animate elements as they leave the DOM using AnimatePresence. This mirrors Motion’s React API and docs for exit animations (reference).

`svelte



{#if show}
initial={{ opacity: 0, scale: 0.9 }}
animate={{ opacity: 1, scale: 1 }}
exit={{ opacity: 0, scale: 0.9 }}
transition={{ duration: 0.5 }}
class="size-24 rounded-md bg-cyan-400"
/>
{/if}


(show = !show)}>Toggle
`

- The exit animation is driven by exit and will play when the element unmounts.
- Transition precedence (merged before running exit):
- exit.transition (highest precedence)
- component transition (merged with MotionConfig)
- fallback default { duration: 0.35 }

#### Current Limitations

Some Motion features are not yet implemented:

- reducedMotion settings
- features configuration
- Performance optimizations like transformPagePoint
- Advanced transition controls
- Shared layout / layoutId (planned)

External Dependencies

This package carefully selects its dependencies to provide a robust and maintainable solution:

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- motion
- High-performance animation library for the web
- Provides smooth, hardware-accelerated animations
- Supports spring physics and custom easing
- Used for creating fluid motion and transitions

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| Motion | Demo / Route | Live Demo |
| -------------------------------------------------------------------------------------------------------- | ---------------------------------------- | ---------------------------------------------------------------------------------------------- |
| React - Enter Animation | /tests/motion/enter-animation | View Example |
| HTML Content (0→100 counter) | /tests/motion/html-content | View Example |
| Aspect Ratio | /tests/motion/aspect-ratio | View Example |
| Hover + Tap (whileHover + whileTap) | /tests/motion/hover-and-tap | View Example |
| Focus (whileFocus) | /tests/motion/while-focus | View Example |
| Rotate | /tests/motion/rotate | View Example |
| Random - Shiny Button by @verse\_ | /tests/random/shiny-button | View Example |
| Fancy Like Button | /tests/random/fancy-like-button | View Example |
| Keyframes (square → circle → square; scale 1→2→1) | /tests/motion/keyframes | View Example |
| Animated Border Gradient (conic-gradient rotate) | /tests/random/animated-border-gradient | View Example |
| Exit Animation | /tests/animate-presence/basic | View Example |

Interactions

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Svelte Motion now supports hover interactions via the whileHover prop, similar to React Motion/Framer Motion.

`svelte

`

- whileHover accepts a keyframes object. It also supports a nested transition to override the global transition for hover only:

`svelte
whileHover={{ scale: 1.05, transition: { duration: 0.12 } }}
transition={{ duration: 0.25 }}
/>
`

- Baseline restoration: when the pointer leaves, changed values are restored to their pre-hover baseline. Baseline is computed from animate values if present, otherwise initial, otherwise sensible defaults (e.g., scale: 1, x/y: 0) or current computed style where applicable.
- True-hover gating: hover behavior runs only on devices that support real hover and fine pointers (media queries (hover: hover) and (pointer: fine)), avoiding sticky hover states on touch devices.

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`svelte

`

- Callbacks: onTapStart, onTap, onTapCancel are supported.
- Accessibility: Elements with whileTap are keyboard-accessible (Enter and Space).
- Enter or Space down → fires onTapStart and applies whileTap (Space prevents default scrolling)
- Enter or Space up → fires onTap
- Blur while key is held → fires onTapCancel
- MotionContainer sets tabindex="0" automatically when whileTap is present and no tabindex/tabIndex is provided.

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`svelte

`

- Animates when the element receives keyboard focus and restores baseline on blur.
- Callbacks: onFocusStart, onFocusEnd are supported.
- Perfect for keyboard navigation and accessibility enhancements.

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`svelte
onAnimationStart={(def) => {
/ ... /
}}
onAnimationComplete={(def) => {
/ ... /
}}
/>
`

Variants

Variants allow you to define named animation states that can be referenced throughout your component tree. They're perfect for creating reusable animations and orchestrating complex sequences.

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Instead of defining animation objects inline, create a Variants object with named states:

`svelte


Click me
`

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One of the most powerful features is automatic propagation through component trees. When a parent changes its animation state, all children with variants defined automatically inherit that state:

`svelte




Item 1
Item 2
Item 3

`

How it works:

- Parent sets animate="visible"
- Children with variants automatically inherit "visible" state
- Each child resolves its own variant definition
- No need to pass animate props to children!

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Create staggered animations with transition delays:

`svelte
{#each items as item, i}

{item}

{/each}
`

See the Variants documentation for complete details and examples.

Server-side rendering

Motion components render their initial state during SSR. The container merges inline style with the first values from initial (or the first keyframes from animate when initial is empty) so the server HTML matches the starting appearance. On hydration, components promote to a ready state and animate without flicker.

`svelte
initial={{ opacity: 0, borderRadius: '12px' }}
animate={{ opacity: 1 }}
style="width: 100px; height: 50px"
/>
`

Notes:

- Transform properties like scale/rotate are composed into a single transform style during SSR.
- When initial is empty, the first keyframe from animate is used to seed SSR styles.
- initial can be false to not run on initial

Utilities

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- Returns a Svelte readable store that updates once per animation frame with elapsed milliseconds since creation.
- If you pass an id, calls with the same id return a shared timeline (kept in sync across components).
- SSR-safe: Returns a static 0 store when window is not available.

`svelte


rotate: ${$rotate}deg} />
`

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- Runs a callback on every animation frame with the current timestamp.
- The callback receives a DOMHighResTimeStamp representing the time elapsed since the time origin.
- Returns a cleanup function that stops the animation loop.
- Best used inside a $effect to ensure proper cleanup when the component unmounts.
- SSR-safe: Does nothing and returns a no-op cleanup function when window is unavailable.

`svelte