neo-bytes

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

Useful for displaying file sizes for humans.

Note that it uses base-10 (e.g. kilobyte). Read about the difference between kilobyte and kibibyte.

This project stands on the shoulders of the great pretty-bytes by Sindre Sorhus.

It is a fork of the original project with additional features.

Install

npm install neo-bytes

Usage

import neoBytes from 'neo-bytes';

neoBytes(1337);
//=> '1.34 kB'

neoBytes(100);
//=> '100 B'

// Display with units of bits
neoBytes(1337, {bits: true});
//=> '1.34 kbit'

// Display file size differences
neoBytes(42, {signed: true});
//=> '+42 B'

// Localized output using German locale
neoBytes(1337, {locale: 'de'});
//=> '1,34 kB'

Migrating from pretty-bytes

Currently, neo-bytes is fully compatible with pretty-bytes.

If you need the additional features of neo-bytes.

You can migrate to neo-bytes in the fastest way by doing the following:

// Before
import prettyBytes from 'pretty-bytes';
//                       ^^^^^^

// After
import prettyBytes from 'neo-bytes';
//                       ^^^

// Or fully use the new name (recommended)
import neoBytes from 'neo-bytes';
//     ^^^            ^^^

Choose the Right Unit

neo-bytes, like the original pretty-bytes, only does basic human-readable conversion.

But I found that in practice. It is really hard to understand how to choose units in different situations.

Here are my suggestions based on a lot of study and practice.

If there is any disagreement, please raise an issue and we can discuss about it.

Memory / CPU Cache Size

Use binary and noi

Follow the JEDEC memory standards, which is the most common standard for memory size.

// A custom function to make it easier
const memorySize = (n) => neoBytes(n, {binary: true, noi: true});

// Example
memorySize(67108864); // 64 * 1024 * 1024
//=> '64 MB'

memorySize(68719476736); // 64 * 1024 * 1024 * 1024
//=> '64 GB'

Storage / Disk / File Size

Use nothing

// A custom function to make it easier
const storageSize = (n) => neoBytes(n);

// Example
storageSize(128000000000); // 128 * 1000 * 1000 * 1000
//=> '128 GB'

// A custom function to make it easier
const diskSize = (n) => neoBytes(n);

diskSize(16000000000000); // 16 * 1000 * 1000 * 1000 * 1000
//=> '16 TB'

// A custom function to make it easier
const fileSize = (n) => neoBytes(n);

// Example
fileSize(1233445);
//=> '1.23 MB'

Link Speed / Network Bandwidth

Use bits, noit and suffix

// A custom function to make it easier
const linkSpeed = (n) => neoBytes(n, {bits: true, noit: true, suffix: 'ps'});

// Example
linkSpeed(1000000000); // 1 * 1000 * 1000 * 1000
//=> '1 Gbps'

Download Speed / File Transfer Speed

Use suffix

// A custom function to make it easier
const downloadSpeed = (n) => neoBytes(n, {suffix: '/s'});

// Example
downloadSpeed(1000000); // 1 * 1000 * 1000
//=> '1 MB/s'

Reference

• Byte
• Bit
• JEDEC memory standards
• Metric prefix
• Binary Prefix

API

neoBytes(number, options?)

number

Type: number

The number to format.

options

Type: object

signed

Type: boolean
Default: false

Include plus sign for positive numbers. If the difference is exactly zero a space character will be prepended instead for better alignment.

bits

Type: boolean
Default: false

Format the number as bits instead of bytes. This can be useful when, for example, referring to bit rate.

binary

Type: boolean
Default: false

Format the number using the Binary Prefix instead of the SI Prefix. This can be useful for presenting memory amounts. However, this should not be used for presenting file sizes.

locale

Type: boolean | string
Default: false (No localization)

Important: Only the number and decimal separator are localized. The unit title is not and will not be localized.

• If true: Localize the output using the system/browser locale.
• If string: Expects a BCP 47 language tag (For example: en, de, …)
• If string[]: Expects a list of BCP 47 language tags (For example: en, de, …)

minimumFractionDigits

Type: number
Default: undefined

The minimum number of fraction digits to display.

If neither minimumFractionDigits or maximumFractionDigits are set, the default behavior is to round to 3 significant digits.

import neoBytes from 'neo-bytes';

// Show the number with at least 3 fractional digits
neoBytes(1900, {minimumFractionDigits: 3});
//=> '1.900 kB'

neoBytes(1900);
//=> '1.9 kB'

maximumFractionDigits

Type: number
Default: undefined

The maximum number of fraction digits to display.

If neither minimumFractionDigits or maximumFractionDigits are set, the default behavior is to round to 3 significant digits.

import neoBytes from 'neo-bytes';

// Show the number with at most 1 fractional digit
neoBytes(1920, {maximumFractionDigits: 1});
//=> '1.9 kB'

neoBytes(1920);
//=> '1.92 kB'

space

Type: boolean
Default: true

Put a space between the number and unit.

import neoBytes from 'neo-bytes';

neoBytes(1920, {space: false});
//=> '1.9kB'

neoBytes(1920);
//=> '1.92 kB'

noi

Type: boolean
Default: false

Remove 'i' from the binary enabled formatted output.

import neoBytes from 'neo-bytes';

neoBytes(1024, {binary: true});
//=> '1 kiB'

neoBytes(1024, {binary: true, noi: true});
//=> '1 kB'

noit

Type: boolean
Default: false

Remove 'it' from the bits enabled formatted output.

import neoBytes from 'neo-bytes';

neoBytes(1337, {bits: true});
//=> '1.34 kbit'

neoBytes(1337, {bits: true, noit: true});
//=> '1.34 kb'

suffix

Type: string
Default: undefined

Suffix to append to the formatted number.

import neoBytes from 'neo-bytes';

neoBytes(1337, {suffix: '/s'});
//=> '1.34 kB/s'

neoBytes(10e8, {bits: true, noit: true, suffix: 'ps'});
//=> '1 Gbps'

neoBytes(10e9, {bits: true, space: false, noit: true, suffix: 'ps'})
//=> '10Gbps'

Related

• pretty-bytes - Original module
• pretty-bytes-cli - CLI for original module
• pretty-ms - Convert milliseconds to a human readable string