Motion UI

Motion System v4.2

Production-ready UI motion system for React / Next.js.

Focused on performance, accessibility, and usability — not decoration.

When to Use

Use this motion system when motion:

• Guides attention (e.g., onboarding, key actions)
• Communicates state (loading, success, error, transitions)
• Preserves spatial continuity (layout changes, navigation)

Appropriate Scenarios

• Interactive components (buttons, modals, menus)
• State transitions (loading → loaded, open → closed)
• Navigation and layout continuity (shared elements, crossfade)

Considerations

• Accessibility: Always support reduced motion
• Device adaptation: Adjust for low-end devices
• Performance trade-offs: Prefer responsiveness over visual smoothness

Avoid Using Motion When

• It is purely decorative
• It reduces usability or clarity
• It impacts performance negatively

How It Works

Core Principle

Motion must:

• Guide attention
• Communicate state
• Preserve spatial continuity

If it does none → remove it.

Installation

npm install motion

Version

• motion/react - default for current Motion for React projects (package: motion)
• framer-motion - legacy import path for projects that still depend on Framer Motion

Do not mix. Mixing causes conflicting internal schedulers and broken AnimatePresence contexts — components from one package will not coordinate exit animations with components from the other.

To check which version your project uses:

cat package.json | grep -E '"motion"|"framer-motion"'

Always import from one source consistently:

// Correct (modern)
import { motion, AnimatePresence } from "motion/react"

// Correct (legacy)
import { motion, AnimatePresence } from "framer-motion"

// Never mix both in the same project

Motion Tokens

// motionTokens.ts
export const motionTokens = {
  duration: {
    fast: 0.18,
    normal: 0.35,
    slow: 0.6
  },
  // Use these as the `ease` value inside a `transition` object:
  // transition={{ duration: motionTokens.duration.normal, ease: motionTokens.easing.smooth }}
  easing: {
    smooth: [0.22, 1, 0.36, 1] as [number, number, number, number],
    sharp:  [0.4,  0, 0.2, 1] as [number, number, number, number]
  },
  distance: {
    sm: 8,
    md: 16,
    lg: 24
  }
}

Usage example:

import { motionTokens } from "@/lib/motionTokens"

<motion.div
  initial={{ opacity: 0, y: motionTokens.distance.md }}
  animate={{ opacity: 1, y: 0 }}
  transition={{
    duration: motionTokens.duration.normal,
    ease: motionTokens.easing.smooth
  }}
/>

Performance Rules

Safe

• transform
• opacity

Avoid

• width / height
• top / left

Rule: responsiveness > smoothness

Device Adaptation

The heuristic combines CPU core count and available memory for a more reliable signal. deviceMemory is available on Chrome/Android; the fallback covers Safari and Firefox.

const isLowEnd =
  typeof navigator !== "undefined" && (
    // Low memory (Chrome/Android only; undefined elsewhere → treat as capable)
    (navigator.deviceMemory !== undefined && navigator.deviceMemory <= 2) ||
    // Few cores AND no memory API (covers Safari/Firefox on weak hardware)
    (navigator.deviceMemory === undefined && navigator.hardwareConcurrency <= 4)
  )

const duration = isLowEnd ? 0.2 : 0.4

Accessibility

JS (useReducedMotion)

import { motion, useReducedMotion } from "motion/react"

export function FadeIn() {
  const reduce = useReducedMotion()

  return (
    <motion.div
      initial={{ opacity: 0, y: reduce ? 0 : 24 }}
      animate={{ opacity: 1, y: 0 }}
    />
  )
}

CSS

@media (prefers-reduced-motion: reduce) {
  .motion-safe-transition {
    transition: opacity 0.2s;
  }

  .motion-reduce-transform {
    transform: none !important;
  }
}

Tailwind

<div class="motion-safe:animate-fade motion-reduce:opacity-100"></div>

Architecture & Patterns

Core Patterns

Why avoid `layout` on large containers? Framer's layout animation uses transform to reconcile positions, but on elements that span the full viewport or trigger deep reflow, the measurement cost causes visible jank and CLS. Prefer CSS Grid/Flexbox transitions or coordinate with layoutId on specific child elements only.

Layout & Transitions

• Shared element transitions → layoutId (must be unique per mounted instance)
• Enter / exit transitions → AnimatePresence (see mode guidance below)

AnimatePresence mode

Always specify mode explicitly — the default ("sync") runs enter and exit simultaneously, which causes visual overlap in most UI patterns.

// Modal — always use "wait"
<AnimatePresence mode="wait">
  {open && <Modal key="modal" />}
</AnimatePresence>

// Dismissible list item — use "popLayout"
<AnimatePresence mode="popLayout">
  {items.map(item => <Card key={item.id} />)}
</AnimatePresence>

Advanced Patterns (Concepts)

• Parallax (scroll-linked transforms)
• Scroll storytelling (sticky sections)
• 3D tilt (pointer-based transforms)
• Crossfade (shared layoutId)
• Progressive reveal (clip-path)
• Skeleton loading (looped opacity)
• Micro-interactions (hover/tap feedback)
• Spring system (physics-based motion)

Modal Essentials

• Focus trap
• Escape close
• Scroll lock
• ARIA roles
• Use AnimatePresence mode="wait" so exit animation completes before the next modal enters

Full Example

import React, { useEffect, useRef, useState } from "react"
import { motion, AnimatePresence } from "motion/react"

function useFocusTrap(ref: React.RefObject<HTMLDivElement | null>, active: boolean) {
  useEffect(() => {
    if (!active || !ref.current) return
    const el = ref.current
    const focusable = el.querySelectorAll<HTMLElement>(
      'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'
    )
    const first = focusable[0]
    const last  = focusable[focusable.length - 1]

    function handleKey(e: KeyboardEvent) {
      if (e.key !== "Tab") return
      if (e.shiftKey && document.activeElement === first) {
        e.preventDefault()
        last?.focus()
      } else if (!e.shiftKey && document.activeElement === last) {
        e.preventDefault()
        first?.focus()
      }
    }

    el.addEventListener("keydown", handleKey)
    first?.focus()
    return () => el.removeEventListener("keydown", handleKey)
  }, [active, ref])
}

function useScrollLock(active: boolean) {
  useEffect(() => {
    if (!active) return
    const prev = document.body.style.overflow
    document.body.style.overflow = "hidden"
    return () => { document.body.style.overflow = prev }
  }, [active])
}

function Modal({ open, closeModal }: { open: boolean; closeModal: () => void }) {
  const ref = useRef<HTMLDivElement>(null)

  useFocusTrap(ref, open)
  useScrollLock(open)

  useEffect(() => {
    function onKey(e: KeyboardEvent) {
      if (e.key === "Escape") closeModal()
    }