jhildenbiddle/css-vars-ponyfill

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

1460 stars · 63 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

A lightweight, dependency-free JavaScript ponyfill that provides client-side support for CSS custom properties (CSS variables) in legacy and modern browsers. It transforms CSS custom properties into static values at runtime, supporting link/style/import stylesheets, chained and nested var() functions, fallback values, and web components with shadow DOM.

Use cases

• support CSS variables in Internet Explorer 9-11
• make CSS custom properties work in legacy browsers
• runtime theming with CSS variables across old and new browsers
• use CSS variables inside web components and shadow DOM
• live-update CSS variable values without page reload
• transform stylesheets to static values client-side

When to choose

• you must support legacy browsers like IE9-IE11 that lack CSS custom property support
• you need runtime/live updates of CSS variable values in older browsers
• your project uses web components or shadow DOM with CSS variables
• you want a small, dependency-free client-side solution

When to avoid

• your target browsers natively support CSS custom properties
• you modify styles via CSSOM APIs, which this library does not support
• you need custom property declarations outside :root and :host rulesets
• you need a true polyfill that patches the CSSOM rather than transforming stylesheets

Facets

library · maturity maintenance

ui-components developer-tools web-development frontend cross-platform browser css-variables ponyfill polyfill legacy-browser-support internet-explorer shadow-dom web-components client-side web-server

Member repositories

For agents

markdown · JSON · MCP: product_card(name="jhildenbiddle/css-vars-ponyfill")