magic-favicon

Live Demo

Tiny, dependency-free favicon state indicators for modern web apps.

magic-favicon turns your tab icon into a compact status surface for progress, notifications, health states, and activity animation without mutating the page title.

Current size snapshot: ~2.5KB gzipped (core ESM build measured on February 25, 2026).

Why this library

• Tiny runtime footprint (optimized for strict size budgets)
• Zero runtime dependencies
• TypeScript-first API
• Modern outputs: ESM, CJS, UMD
• Works in background tabs with worker-backed ticker fallback logic
• High-DPI aware canvas rendering for sharper badge text/icons

Features

Capability	Method	Notes
Progress bar	progress(value)	Horizontal bottom bar, clamped 0..100
Pie progress	pie(value)	Circular ring progress, clamped 0..100
Badge count	badge(count)	Auto formats to 99+
Status indicator	status(kindOrColor)	Built-in states or custom color string
Pulse animation	pulse(options)	Soft radial activity pulse
Spin animation	spin(options)	Indeterminate ring spinner
Reset	reset() / clear()	Restores original favicon
Global defaults	setDefaults(options)	Reuse shared config across calls

Install

npm install magic-favicon

Quick start

import favicon from "magic-favicon";

favicon.progress(35);
favicon.pie(72);
favicon.badge(5);
favicon.status("warning");
favicon.status("#7c3aed"); // custom status color
favicon.pulse();
favicon.spin();
favicon.reset();

favicon.badge(8, { sizeRatio: 1.25 });

Framework recipes

All framework integrations follow the same rule: call magic-favicon only on the client.

React 19+

import { useEffect } from "react";
import favicon from "magic-favicon";

export function UploadTabStatus({ progress }: { progress: number }) {
  useEffect(() => {
    favicon.progress(progress, { preserveBase: true });
    return () => favicon.reset();
  }, [progress]);

  return null;
}

Next.js (App Router)

"use client";

import { useEffect } from "react";
import favicon from "magic-favicon";

export default function RealtimeIndicator() {
  useEffect(() => {
    favicon.spin({ color: "#f59e0b" });
    return () => favicon.reset();
  }, []);

  return null;
}

Angular v21 (standalone + signals)

import { Component, DestroyRef, effect, inject, PLATFORM_ID, signal } from "@angular/core";
import { isPlatformBrowser } from "@angular/common";
import favicon from "magic-favicon";

@Component({
  selector: "app-upload-status",
  standalone: true,
  template: `{{ progress() }}%`
})
export class UploadStatusComponent {
  progress = signal(0);
  private platformId = inject(PLATFORM_ID);
  private destroyRef = inject(DestroyRef);

  constructor() {
    if (!isPlatformBrowser(this.platformId)) return;

    effect(() => {
      favicon.progress(this.progress());
    });

    this.destroyRef.onDestroy(() => favicon.reset());
  }
}

Vue 3+

<script setup lang="ts">
import { onMounted, onBeforeUnmount } from "vue";
import favicon from "magic-favicon";

onMounted(() => favicon.badge(6, { preserveBase: true }));
onBeforeUnmount(() => favicon.reset());
</script>

Nuxt 3+

<script setup lang="ts">
import { onMounted, onBeforeUnmount } from "vue";
import favicon from "magic-favicon";

onMounted(() => favicon.status("success"));
onBeforeUnmount(() => favicon.reset());
</script>

SvelteKit / Svelte 5

<script lang="ts">
  import { onMount } from "svelte";
  import favicon from "magic-favicon";

  onMount(() => {
    favicon.pulse({ preserveBase: true });
    return () => favicon.reset();
  });
</script>

API

setDefaults(options)

Set global defaults merged into subsequent method calls.

favicon.setDefaults({
  preserveBase: true,
  color: "#0ea5e9",
  trackColor: "rgba(0,0,0,0.25)",
  lineWidth: 4
});

progress(value, options?)

Options:

• color?: string
• trackColor?: string
• heightRatio?: number (0.1..0.6)
• sizeRatio?: number (0.4..1.6)
• preserveBase?: boolean

pie(value, options?)

Options:

• color?: string
• trackColor?: string
• lineWidth?: number (2..10)
• sizeRatio?: number (0.4..1.6)
• preserveBase?: boolean

badge(count, options?)

Options:

• bgColor?: string
• textColor?: string
• position?: 'tr' | 'tl' | 'br' | 'bl'
• sizeRatio?: number (0.4..1.6)
• preserveBase?: boolean

Behavior:

• count <= 0 triggers reset
• count > 99 displays 99+

status(kindOrColor, options?)

kindOrColor can be:

• 'success'
• 'warning'
• 'error'
• any CSS color string (custom)

Options:

• successColor?: string
• warningColor?: string
• errorColor?: string
• shape?: 'dot' | 'ring' | 'square'
• ringWidth?: number
• sizeRatio?: number (0.4..1.6)
• preserveBase?: boolean

pulse(options?) and spin(options?)

Options:

• color?: string
• periodMs?: number (min 300)
• tickMs?: number (min 16)
• lineWidth?: number (spin ring width)
• sizeRatio?: number (0.4..1.6)
• preserveBase?: boolean

reset(), clear(), destroy()

• reset() restores original favicon attributes.
• clear() is an alias for reset().
• destroy() stops running animations.

Factory API

import { createMagicFavicon } from "magic-favicon";

const faviconA = createMagicFavicon();
const faviconB = createMagicFavicon();

Real-world patterns

Upload progress

favicon.progress(0);

upload.on("progress", (p: number) => {
  favicon.progress(p);
});

upload.on("done", () => {
  favicon.status("success");
});

Notifications

favicon.badge(unreadCount, { bgColor: "#dc2626" });

Live connection state

socket.on("open", () => favicon.status("success"));
socket.on("reconnecting", () => favicon.spin({ color: "#f59e0b" }));
socket.on("error", () => favicon.status("error"));

Browser support

Modern evergreen browsers with Canvas API support.

Local development

pnpm install
pnpm run build
pnpm run test
pnpm run size
pnpm run size:check
pnpm run dev

• Demo app: demo/
• Source: src/index.ts

Size policy

The project includes a gzip size check script and enforces a hard budget of 5KB max for dist/index.js.gz.

• Latest measured size: 2503 bytes gzipped (February 25, 2026)
• CI fails if size exceeds the 5KB budget

Release workflow (Changesets + pnpm)

pnpm changeset

Then commit the generated file under .changeset/.

On main pushes, GitHub Actions will:

1. run pnpm run check
2. open/update a release PR if unpublished changesets exist
3. publish to npm when the release PR is merged

Required GitHub repository secrets:

• NPM_TOKEN

License

MIT