prefix-si

library1.2.0jsnpmunverified

A JavaScript library for formatting numbers with SI, IEC, and BS1852 prefixes. Supports binary (KiB/MiB), metric (k/M/G), and BS1852 (e.g., 4K7) styles. Current stable version 1.2.0. TypeScript types included. Lightweight with no dependencies. Comparable to filesize.js but with BS1852 support.

productivity

npm install prefix-si

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · PREFIX-SI

prefix-si

productivityjavascriptv1.2.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

prefix

✓ import prefix from 'prefix-si'

✗ const { prefix } = require('prefix-si')

Default export is the function itself; no named export 'prefix'.

default import

✓ import prefix from 'prefix-si'

✗ import { prefix } from 'prefix-si'

Only default export exists.

require

✓ const prefix = require('prefix-si')

✗ const { prefix } = require('prefix-si')

CommonJS require returns the function directly.

Showcases three formatting modes (metric, binary, BS1852) with the prefix function.

import prefix from 'prefix-si'; // Metric: 1200 g → 1.2 kg console.log(prefix(1200, 'g')); // Binary: 1048576 bytes → 1 MiB console.log(prefix(1048576, 'B', { binary: true })); // BS1852: 4700 Ω → 4K7 console.log(prefix(4700, 'R', { bs1852: true })); // Custom SI prefix example console.log(prefix(3.14e6, 'm', { si: true })); // 3.14 Mm

Debug

Known issues

gotchaDefault export is a function; do not destructure import.

fix

Use `import prefix from 'prefix-si'` instead of destructuring.

affects: >=1.0.0

breakingIn version 1.0.0, the library switched to ES module. CommonJS require still works but returns a different shape? (Check docs)

fix

Use `import` syntax or use `require('prefix-si').default` if using CJS.

affects: >=1.0.0 <2.0.0

deprecatedOptions `binary` and `si` flags may be deprecated in future versions. (Check docs)

fix

Use explicit prefix style option instead.

affects: >=1.0.0

gotchaBS1852 output uses uppercase letters (e.g., 'K' for kilo), not lowercase.

fix

When parsing BS1852 output, expect uppercase prefix letters.

affects: >=1.0.0

gotchaLarge numbers (>1e21) may produce unexpected results due to JavaScript number precision.

fix

Use a big number library for extremely large values.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: (0 , _prefixSi.default) is not a function

Using ES import with TypeScript but module resolution not set to ESM.

fix

Set `"module": "ESNext"` or use `const prefix = require('prefix-si')`.

prefix is not a function

Destructured import: `import { prefix } from 'prefix-si'`.

fix

Use `import prefix from 'prefix-si'`.

Cannot find module 'prefix-si'

Package not installed or misspelled.

fix

Run `npm install prefix-si` and check spelling.

Upgrade

Version history

1.2.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubssh://git@github.com/mleko/js-prefix-si ↗

packageprefix-si ↗

homepagehttps://github.com/mleko/js-prefix-si#readme ↗