Magnet Lines
A grid of short bars that turn to point at the pointer like iron filings around a magnet, each easing toward its angle so a sweep leaves a ripple of turning bars behind it.
- Category: Backgrounds
- Licence: Charcoal UI Pro
- Built with: React 19, Tailwind CSS 4, Motion
- Dependencies: motion, clsx, tailwind-merge
Examples
Magnet Lines
API reference
| Prop | Type | Default | Description |
|---|---|---|---|
rows | number | 9 | |
cols | number | 15 | |
length | number | 0.6 | Bar length as a fraction of the cell. |
color | string | "var(--foreground)" | |
lerp | number | 0.18 | How quickly bars turn. |
thickness | number | 2 | |
className | string | — |
About Magnet Lines
Magnet Lines fills a grid with short bars that turn to point at the pointer like iron filings around a magnet, easing so a sweep leaves a ripple of turning bars.
Magnet Lines is an animated background for React 19, styled with Tailwind CSS 4 and animated with Motion. It drops into Next.js, Vite, Remix or Astro through the shadcn CLI as a single file you own.
When to use Magnet Lines
- Physics and engineering brands.
- Interactive heroes.
- Developer playgrounds.
- Tech product pages.
How it works
Each bar eases its angle the shortest way toward the pointer, and only redraws while moving. It runs on a canvas capped at 2x pixel density, pauses when scrolled off screen, and reads its colours from your theme tokens so it follows dark mode.
The whole layer is decorative and aria-hidden, sits behind your content without taking pointer events it does not need, and pauses when scrolled off screen. With prefers-reduced-motion on, it holds still or settles instantly instead of animating.
Customizing Magnet Lines
Every prop is documented in the API reference above with its type and default. The ones you will reach for first are listed here.
The Customize panel next to the preview lets you change rows, cols, length, lerp live, and the Code tab updates to match, so the snippet you copy already carries your values.
- rows (number, default 9).
- cols (number, default 15).
- length (number, default 0.6): Bar length as a fraction of the cell.
- color (string, default "var(--foreground)").
- lerp (number, default 0.18): How quickly bars turn.
- thickness (number, default 2).
Goes well with Magnet Lines
These backgrounds pieces share its tokens and motion language, so they sit together on one page without clashing.
- Ember Field: An animated React ember background: glowing embers drift up and flicker as they cool
- Smoke: A slow React smoke background: blurred plumes drifting over dark sections, CSS only
- Aurora: An animated React aurora background: soft light bands drifting across a section
- Grid Beams: A React grid background with beams of light running along its lines
- Meteors: A React meteor shower background: streaks falling diagonally, CSS only
Install Magnet Lines
npx shadcn@latest add @charcoal/magnet-linesMagnet Lines is part of Charcoal UI Pro. One seat unlocks all 300 Pro components, 107 landing-page sections and 100 full templates, for every personal and client project, with updates included. Add the @charcoal registry once with your access token, then the command above copies magnet-lines.tsx into components/ui and installs clsx, tailwind-merge.
You own the file you install: no runtime package, no lock-in, nothing to keep in sync. Change it however your product needs.
See Charcoal UI Pro pricing · Pro setup
Frequently asked questions
- How do I install Magnet Lines?
- Magnet Lines is part of Charcoal UI Pro. Add the @charcoal registry to components.json with your access token, then run npx shadcn@latest add @charcoal/magnet-lines. It copies magnet-lines.tsx into components/ui and installs motion, clsx, tailwind-merge.
- Is Magnet Lines free for commercial use?
- Magnet Lines needs a Charcoal UI Pro seat, monthly or a one-time lifetime price. A seat covers unlimited personal and commercial projects, including client work, and every future Pro component.
- Does Magnet Lines work with Next.js?
- Yes. It is a client component for React 19 styled with Tailwind CSS 4, so it works in the Next.js App Router and Pages Router, Vite, Remix and Astro.
- Can an AI coding agent install Magnet Lines?
- Yes. Connect the Charcoal UI MCP server (https://charcoalui.com/mcp) to Claude Code, Cursor or any MCP client; get_component returns Magnet Lines's props and get_install_command returns the exact command.