data-formatters

Utility library for formatting numbers, currency, percentages, dates, time, bytes, and text using modern Intl APIs. This project provides small, reusable helpers to standardize value formatting in frontend applications.

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Features

• Currency formatting
• Compact currency formatting
• Number formatting
• Compact numbers
• Percent formatting
• Compact percent formatting
• Date formatting
• Date/time formatting
• Relative time formatting
• Duration formatting
• Bytes formatting
• Name normalization (Title Case)
• Locale support (Intl)
• Lightweight and dependency-free

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Installation

npm install data-formatters

or

yarn add data-formatters

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Usage

import {
  formatBytes,
  formatCurrency,
  formatDate,
  formatDateTime,
  formatDuration,
  formatCompactCurrency,
  formatNumber,
  formatCompactNumber,
  formatPercent,
  formatCompactPercent,
  formatName,
  formatRelativeTime
} from "data-formatters"

Currency

formatCurrency(1200, {
  currency: "USD",
  locale: "en-US"
})

Result:

$1,200.00

Compact Currency

formatCompactCurrency(1200000, {
  currency: "USD",
  locale: "en-US"
})

Result:

$1.2M

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Numbers

formatNumber(1200, { locale: "en-US" })

Result:

1,200

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Compact Numbers

formatCompactNumber(1500, { locale: "en-US" })

Result:

1.5K

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Percent

formatPercent(0.25, { locale: "en-US" })

Result:

25%

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Compact Percent

formatCompactPercent(0.1234, { locale: "en-US" })

Result:

12.3%

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Name Formatting

formatName("victor hugo lima")

Result:

Victor Hugo Lima

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Bytes

formatBytes(1536)

Result:

1.5 KB

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Date

formatDate("2026-03-09T00:00:00Z", {
  locale: "en-US",
  timeZone: "UTC"
})

Result:

03/09/2026

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DateTime

formatDateTime("2026-03-09T14:30:00Z", {
  locale: "en-US",
  timeZone: "UTC",
  dateStyle: "medium",
  timeStyle: "short"
})

Result:

Mar 9, 2026, 2:30 PM

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Duration

formatDuration(3665)

Result:

1h 1m 5s

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Relative Time

formatRelativeTime(-1, "day", "en-US")

Result:

yesterday

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Locale Support

The library uses the native Intl API, so formatting behavior depends on the provided locale. Examples:

Locale	Number Example
en-US	1,000
pt-BR	1.000
de-DE	1.000

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Testing

Tests are written using Vitest. Run locally:

npm test

Run in watch mode:

npm run test:watch

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Development

Clone the repository:

git clone https://github.com/vhlima1008/data-formatters.git

Install dependencies:

npm install

Build:

npm run build

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Contributing

Contributions are welcome! Steps:

1. Fork the repository
2. Create a branch

git checkout -b feature/my-feature

3. Commit your changes
4. Push the branch
5. Open a Pull Request

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License

Distributed under the MIT License. See LICENSE for more information.

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Author

Victor Hugo Lima Monteiro GitHub: https://github.com/vhlima1008