Numera

Dependency-free animated number text for React counters, prices, stats, OTP slots, and compact metrics.

Installation

npm install numera

react is the only peer dependency.

Usage

import Numera from 'numera';
import 'numera/style.css';

<Numera value={123456} />;

Use Intl.NumberFormat options for currency, compact notation, percentages, signs, decimals, and locale-aware separators:

<Numera
  value={79187}
  locales="en-US"
  format={{ style: 'currency', currency: 'USD' }}
/>;

<Numera
  value={3300000}
  format={{ notation: 'compact', maximumFractionDigits: 1 }}
  suffix=" views"
/>;

Animated Parts

Numera animates formatted number parts as first-class pieces. Digits roll, separators move, and symbols like $, ,, ., %, +, -, compact labels, prefixes, and suffixes can enter, exit, or crossfade with the number.

<Numera
  value={temperature}
  format={{ signDisplay: 'exceptZero', maximumFractionDigits: 1 }}
  suffix=" deg"
/>;

Spring Animations

Use presets for quick tuning:

<Numera value={score} preset="soft" />;
<Numera value={score} preset="snappy" />;
<Numera value={score} preset="springy" />;

Or pass timing options directly. Springs are generated as CSS timing functions, so there is no runtime animation dependency.

<Numera
  value={score}
  timing={{
    duration: 420,
    spring: { mass: 1.2, stiffness: 150, damping: 19 },
  }}
/>;

Fixed Slots

Use Numera directly for OTP and code-input slots. Give each slot a stable width, disable layout correction, and pass animationKey when the visible state changes even if the displayed number is still 0.

const digit = code[index] ?? '';
const isFilled = digit.length > 0;
const displayDigit = isFilled ? Number(digit) : 0;

<Numera
  value={displayDigit}
  preset="soft"
  trend={isFilled ? 'up' : 'down'}
  animationKey={`${isFilled ? 'filled' : 'empty'}:${displayDigit}`}
  layoutCorrection={false}
/>;

Vanilla Usage

import { NumeraController } from 'numera/vanilla';
import 'numera/vanilla.css';

const numera = new NumeraController({
  element: document.querySelector('[data-numera]')!,
  value: 1284,
});

numera.update(1300);

Documentation

See the full docs draft for API details, timing options, examples, and notes for specific use cases.

Security

Please report security issues privately using the guidance in .github/SECURITY.md.

Contributing

Install dependencies:

npm install

Run the playground:

npm run dev

Run checks:

npm run check

Build the package:

npm run build

Other Projects

You might also like:

• number-flow - Animated number component by Maxwell Barvian.
• torph - Dependency-free animated text morphing.

License

MIT.