# triggerjs/trigger

A library for creating scroll-based animation with HTML attributes and CSS variables.

Repository: https://github.com/triggerjs/trigger
Canonical: https://ross.abutalabs.com/products/trigger
Language: TypeScript
License: MIT
License Family: permissive
Topics: css, javascript, animation, animation-library, animation-css
Last push: 2025-05-10T00:40:01+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 20, release rhythm 8, longevity 100
- inputs: {"age_days": 1779, "days_push": 481, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1266, forks 74 (observed 2026-08-28T04:04:11.241644+00:00)

## What it is
Trigger JS is a small TypeScript library that creates scroll-based animations using HTML attributes and CSS variables, without writing JavaScript. It binds scroll position to CSS custom properties that you consume in your stylesheets.

## Use cases
- animate elements based on scroll position without writing JavaScript
- scrub a video-like animation forward and backward by scrolling
- bind scroll progress to a CSS variable for transforms and styles
- add scroll-triggered effects to a webpage using only HTML attributes
- create parallax or reveal animations with pure CSS

## When to choose
- you want scroll-driven animations without a JavaScript animation framework
- you prefer configuring animations declaratively via HTML attributes
- your animations can be expressed purely in CSS using variables

## When to avoid
- you need complex timeline-based or physics-based animation logic
- you need scroll animations in a non-browser environment
- you want keyframe-based animation libraries like GSAP with rich easing controls

## Facets
- artifact type: library
- maturity: active
- function: animation, frontend-framework
- domain: web-development, frontend, web-design
- platform: browser
- tags: scroll-animation, css-variables, html-attributes, no-javascript, typescript, javascript

## Member repositories
- triggerjs/trigger (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:11.241644+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T05:03:49.121053+00:00, confidence not recorded.
  - readme: https://github.com/triggerjs/trigger (fetched 2026-08-28T04:04:11.241644+00:00, sha e08390d65f59)
- Data as of 2026-08-30T08:39:29.467469+00:00.