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prinzhorn/skrollr

★ 18,416HTMLAudience · vibe coderComplexity · 2/5DormantLicenseSetup · easy

TLDR

A JavaScript library for creating scroll-triggered animations in HTML without needing a framework or coding skills, just add data attributes to elements and watch them animate as users scroll.

Mindmap

mindmap
  root((skrollr))
    What it does
      Scroll-triggered animations
      CSS interpolation
      Cross-browser support
    How to use
      Data attributes in HTML
      CSS keyframe syntax
      No JavaScript required
    Platforms
      Desktop browsers
      Mobile devices
      Android and iOS
    Features
      Easing functions
      Absolute positions
      Relative positions
      Plugin ecosystem

Things people build with this

USE CASE 1

Build parallax scrolling effects where background images move at different speeds than foreground content.

USE CASE 2

Create animated hero sections that fade, scale, or rotate as visitors scroll down the page.

USE CASE 3

Design interactive landing pages with elements that reveal or transform based on scroll position.

USE CASE 4

Add smooth color transitions and opacity changes to elements triggered by user scrolling.

Tech stack

JavaScriptHTMLCSS

Getting it running

Difficulty · easy Time to first run · 5min
Use freely for any purpose including commercial, as long as you keep the copyright notice.

In plain English

Skrollr is a JavaScript library for creating scroll-based animations on both desktop browsers and mobile devices (including Android and iOS). It works without any other JavaScript libraries and requires no JavaScript skills to use for basic animations, you define your animations directly in HTML using standard data attributes and plain CSS syntax. The core idea is that you attach keyframes to HTML elements by adding data attributes that correspond to scroll positions. As the user scrolls the page, skrollr interpolates between the CSS values you define at each keyframe. For example, you could specify that a background color should transition from blue to red over the first 500 pixels of scrolling, or that an element should rotate as it leaves the viewport. Non-linear easing functions can be applied on a per-property basis. The library handles cross-browser CSS prefixes automatically and supports both absolute keyframe positions (measured in pixels from the top of the page) and relative positions (measured relative to where an element sits in the viewport). Several official and third-party plugins extend its functionality, including hash-based navigation and keyframes defined in separate CSS files. The readme notes the project has not been actively developed since around September 2014, and the author cautions against using it in production, particularly because mobile browser support has always been difficult and newer browser versions may introduce compatibility issues.

Copy-paste prompts

Prompt 1
Show me how to set up skrollr to make a background image move slower than the page scroll (parallax effect).
Prompt 2
How do I use skrollr data attributes to fade out an element as it scrolls out of view?
Prompt 3
Create a skrollr example where a box rotates 360 degrees over the first 1000 pixels of page scroll.
Prompt 4
What's the syntax for defining multiple keyframes on a single element in skrollr using data attributes?
Prompt 5
How do I apply an easing function to a skrollr animation so it doesn't move at constant speed?
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Generated 2026-05-18 · Model: sonnet-4-6 · Verify against the repo before relying on details.