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cubiq/iscroll

12,823JavaScriptAudience · developerComplexity · 2/5Setup · easy

TLDR

A tiny 4KB JavaScript library that adds smooth, customizable scrolling to web pages and mobile apps, with separate variants for zooming, real-time position tracking, and memory-efficient infinite lists.

Mindmap

mindmap
  root((iScroll))
    What it does
      Smooth scrolling
      Mobile touch support
      Custom scroll control
    Variants
      Standard version
      Lite version
      Probe version
      Zoom version
      Infinite version
    Features
      Scroll position events
      Custom animation curves
      Real-time tracking
    Usage
      Wrap content in div
      Initialize with JS
      Configure options
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Code map

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Things people build with this

USE CASE 1

Add smooth touch-scrolling to a mobile web app content area that the device browser cannot natively scroll.

USE CASE 2

Build a memory-efficient infinite-scroll list that recycles DOM elements so thousands of items stay fast.

USE CASE 3

Add pinch-to-zoom to an image gallery or map on a mobile web page using the iScroll zoom variant.

USE CASE 4

Read the exact scroll position in real time during a swipe gesture to drive a parallax effect or custom progress bar.

Tech stack

JavaScript

Getting it running

Difficulty · easy Time to first run · 5min

In plain English

iScroll is a small JavaScript library that adds smooth scrolling to web pages and apps, particularly on mobile devices where browser scrolling has historically been slow or limited. When you have a list, a photo gallery, or any scrollable area inside a web page, iScroll can control how that content moves when a user swipes or drags across it. The library weighs about 4 kilobytes, works without depending on any other library, and runs across a wide range of devices including older Android phones, iPhones, and desktop browsers. It does not just replicate native scrolling, it adds extra control that browsers do not normally expose. Developers can read the exact scroll position at any moment, hook into events that fire before and after scrolling, and set custom animation curves for how content decelerates after a swipe. The project ships in several versions so you can pick the one that fits your use case. The standard version covers most situations. A stripped-down lite version is the smallest and fastest option for pages that only need basic mobile scrolling. A probe version is optimized for reading the scroll position in real time during movement. A zoom version adds pinch-to-zoom on top of scrolling. An infinite version handles very long lists efficiently by recycling elements in memory rather than loading everything at once. To use iScroll you wrap the scrollable content in a container element in your HTML, then pass that container to the iScroll constructor in JavaScript. Configuration options control things like whether a scrollbar appears, whether the mouse wheel works, and which CSS technique the engine uses internally. The readme is a detailed technical guide written for web developers. It covers initialization, configuration options, events, and known limitations with certain CSS properties. The full README is longer than what was shown.

Copy-paste prompts

Prompt 1
Using iScroll, show me the HTML structure and JavaScript setup for a horizontally scrolling card gallery that works on both mobile touch and desktop mouse wheel.
Prompt 2
I am using iScroll infinite version. Help me implement a list that fetches new items from an API as the user scrolls down, recycling DOM nodes to keep memory usage flat.
Prompt 3
Using iScroll zoom version, add pinch-to-zoom to my product image gallery, show me initialization code and how to configure minimum and maximum zoom levels.
Prompt 4
My iScroll container stops responding to touch after I dynamically add items to it. What method do I need to call to refresh the scroll dimensions, and when exactly should I call it?
Prompt 5
Using iScroll probe version, show me how to read the Y scroll position in real time during a swipe and animate a custom progress bar that moves as the user scrolls.
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