The spring() Store: Physics-Based Animation
Animate values with configurable stiffness and damping for a natural feel.
The spring() Store: Physics-Based Animation is a free Sveltejs Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Sveltejs Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Spring Physics
The spring store animates values with stiffness and damping, like a real spring.
Import
From svelte/motion.
import { spring } from "svelte/motion";Create a Spring
Pass an initial value and options.
const pos = spring({ x: 0, y: 0 }, { stiffness: 0.2, damping: 0.4 });Update Target
Set a new target; the value animates toward it.
pos.set({ x: 100, y: 50 });Subscribe with $
Use the value reactively in markup.
<div style="transform: translate({$pos.x}px, {$pos.y}px);"></div>Mouse Following
Update the spring target with mouse coordinates for natural pointer following.
Hard Set
Pass { hard: true } to jump immediately.
pos.set({x: 0, y: 0}, { hard: true });Stiffness
Higher stiffness = faster snap toward target.
Damping
Higher damping = less oscillation. 1 means no bounce.
Vectors and Objects
Springs interpolate numeric values inside arrays and nested objects.
Performance
Springs use rAF internally. They are smooth even for many simultaneous instances.
Quick Check
What does spring stiffness control?
Recap
spring stores animate with physics. Tune stiffness and damping for the desired feel.
Frequently asked questions
Is the “The spring() Store: Physics-Based Animation” lesson free?
Yes — the full text of “The spring() Store: Physics-Based Animation” is free to read here on the web, and the Sveltejs Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Sveltejs Academy course, upgrade to CoddyKit PRO.
What will I learn in “The spring() Store: Physics-Based Animation”?
Animate values with configurable stiffness and damping for a natural feel. You practise Sveltejs Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Sveltejs Academy?
No prior experience is required. Sveltejs Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “The spring() Store: Physics-Based Animation” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Sveltejs Academy lesson?
Yes. Every Sveltejs Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- The spring() Store: Physics-Based Animation
- The tweened() Store: Duration and Easing
- Interpolation Functions
- Animating SVG Paths with Motion