pretty-bytes

  • Version 7.2.0
  • Published
  • 25.1 kB
  • No dependencies
  • MIT license

Install

npm i pretty-bytes
yarn add pretty-bytes
pnpm add pretty-bytes

Overview

Convert bytes to a human readable string: 1337 → 1.34 kB

Index

Functions

Type Aliases

Functions

function prettyBytes

prettyBytes: (number: number | bigint, options?: Options) => string;
  • Convert bytes to a human readable string: 1337 → 1.34 kB.

    Parameter number

    The number to format.

    A bigint of any size is accepted. Past roughly 1e332 bytes the scaled value no longer fits a number, and it is written out in full from the exact quotient, so it carries no grouping and no localized decimal separator, the same as a value below 1e-100.

    Byte counts are otherwise formatted with the precision of a JavaScript number, which holds about 16 significant digits, so above roughly 1e17 bytes the trailing digits of the output may not be exact. A value that rounds up onto a unit boundary can therefore be printed in the larger unit, so 999499999999999999 bytes is 1 EB rather than 999 PB.

    Note: Rounding uses Number#toPrecision, so at an exact tie the direction comes from how that value is stored as a floating point number. 1005 bytes is 1.005 kB and rounds down to 1 kB, while 1125 bytes is 1.125 kB and rounds up to 1.13 kB.

    Example 1

    import prettyBytes from 'pretty-bytes';
    prettyBytes(1337);
    //=> '1.34 kB'
    prettyBytes(100);
    //=> '100 B'
    // Display file size differences
    prettyBytes(42, {signed: true});
    //=> '+42 B'
    // Localized output using German locale
    prettyBytes(1337, {locale: 'de'});
    //=> '1,34 kB'

Type Aliases

type Options

type Options = {
/**
Include plus sign for positive numbers. If the difference is exactly zero a space character will be prepended instead for better alignment.
@default false
*/
readonly signed?: boolean;
/**
- If `false`: Output won't be localized.
- If `true`: Localize the output using the system/browser locale.
- If `string`: Expects a [BCP 47 language tag](https://en.wikipedia.org/wiki/IETF_language_tag) (For example: `en`, `de`, …)
- If `string[]`: Expects a list of [BCP 47 language tags](https://en.wikipedia.org/wiki/IETF_language_tag) (For example: `en`, `de`, …)
Only the number and decimal separator are localized. The unit title is not and will not be localized.
Note: A value below `1e-100` bytes needs more than the 100 fraction digits `Intl.NumberFormat` accepts, so it is written out with plain digits instead of a localized decimal separator.
@default false
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1337, {locale: 'de'});
//=> '1,34 kB'
```
*/
readonly locale?: boolean | string | readonly string[];
/**
Format the number as [bits](https://en.wikipedia.org/wiki/Bit) instead of [bytes](https://en.wikipedia.org/wiki/Byte). This can be useful when, for example, referring to [bit rate](https://en.wikipedia.org/wiki/Bit_rate).
@default false
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1337, {bits: true});
//=> '1.34 kbit'
```
*/
readonly bits?: boolean;
/**
Format the number using the [Binary Prefix](https://en.wikipedia.org/wiki/Binary_prefix) instead of the [SI Prefix](https://en.wikipedia.org/wiki/SI_prefix). This can be useful for presenting memory amounts. However, this should not be used for presenting file sizes.
@default false
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1000, {binary: true});
//=> '1000 B'
prettyBytes(1024, {binary: true});
//=> '1 KiB'
```
*/
readonly binary?: boolean;
/**
The minimum number of fraction digits to display.
@default undefined
If neither `minimumFractionDigits` nor `maximumFractionDigits` is set, the default behavior is to round to 3 significant digits.
Must be an integer between 0 and 100. Throws a `TypeError` for invalid values.
Must not be greater than `maximumFractionDigits`, which throws a `RangeError` when both are set.
Note: When `minimumFractionDigits` or `maximumFractionDigits` is specified, values are truncated instead of rounded to provide more intuitive results for file sizes.
@example
```
import prettyBytes from 'pretty-bytes';
// Show the number with at least 3 fractional digits
prettyBytes(1900, {minimumFractionDigits: 3});
//=> '1.900 kB'
prettyBytes(1900);
//=> '1.9 kB'
```
*/
readonly minimumFractionDigits?: number;
/**
The maximum number of fraction digits to display.
@default undefined
If neither `minimumFractionDigits` nor `maximumFractionDigits` is set, the default behavior is to round to 3 significant digits.
Must be an integer between 0 and 100. Throws a `TypeError` for invalid values.
Must not be less than `minimumFractionDigits`, which throws a `RangeError` when both are set.
Note: When `minimumFractionDigits` or `maximumFractionDigits` is specified, values are truncated instead of rounded to provide more intuitive results for file sizes.
@example
```
import prettyBytes from 'pretty-bytes';
// Show the number with at most 1 fractional digit
prettyBytes(1920, {maximumFractionDigits: 1});
//=> '1.9 kB'
prettyBytes(1920);
//=> '1.92 kB'
```
*/
readonly maximumFractionDigits?: number;
/**
Put a space between the number and unit.
@default true
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1920, {space: false});
//=> '1.92kB'
prettyBytes(1920);
//=> '1.92 kB'
```
*/
readonly space?: boolean;
/**
Use a non-breaking space instead of a regular space to prevent the unit from wrapping to a new line.
Has no effect when `space` is `false`.
@default false
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1337, {nonBreakingSpace: true});
//=> '1.34\u00A0kB'
prettyBytes(1337, {space: false, nonBreakingSpace: true});
//=> '1.34kB'
```
*/
readonly nonBreakingSpace?: boolean;
/**
Pad the output to a fixed width by right-aligning it.
Useful for creating aligned columns in tables or progress bars.
If the output is longer than the specified width, no padding is applied.
Must be a non-negative integer. Throws a `TypeError` for invalid values.
@default undefined
@example
```
import prettyBytes from 'pretty-bytes';
prettyBytes(1337, {fixedWidth: 10});
//=> ' 1.34 kB'
prettyBytes(100_000, {fixedWidth: 10});
//=> ' 100 kB'
// Useful for progress bars and tables
[1000, 10_000, 100_000].map(bytes => prettyBytes(bytes, {fixedWidth: 8}));
//=> [' 1 kB', ' 10 kB', ' 100 kB']
```
*/
readonly fixedWidth?: number;
};

    Package Files (1)

    Dependencies (0)

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    Dev Dependencies (3)

    Peer Dependencies (0)

    No peer dependencies.

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