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html-encoding-sniffer (2.0.1)

Published 2026-02-24 13:57:46 +00:00 by atheaadmin

Installation

registry=
npm install html-encoding-sniffer@2.0.1
"html-encoding-sniffer": "2.0.1"

About this package

Determine the Encoding of a HTML Byte Stream

This package implements the HTML Standard's encoding sniffing algorithm in all its glory. The most interesting part of this is how it pre-scans the first 1024 bytes in order to search for certain <meta charset>-related patterns.

const htmlEncodingSniffer = require("html-encoding-sniffer");
const fs = require("fs");

const htmlBuffer = fs.readFileSync("./html-page.html");
const sniffedEncoding = htmlEncodingSniffer(htmlBuffer);

The returned value will be a canonical encoding name (not a label). You might then combine this with the whatwg-encoding package to decode the result:

const whatwgEncoding = require("whatwg-encoding");
const htmlString = whatwgEncoding.decode(htmlBuffer, sniffedEncoding);

Options

You can pass two potential options to htmlEncodingSniffer:

const sniffedEncoding = htmlEncodingSniffer(htmlBuffer, {
  transportLayerEncodingLabel,
  defaultEncoding
});

These represent two possible inputs into the encoding sniffing algorithm:

  • transportLayerEncodingLabel is an encoding label that is obtained from the "transport layer" (probably a HTTP Content-Type header), which overrides everything but a BOM.
  • defaultEncoding is the ultimate fallback encoding used if no valid encoding is supplied by the transport layer, and no encoding is sniffed from the bytes. It defaults to "windows-1252", as recommended by the algorithm's table of suggested defaults for "All other locales" (including the en locale).

Credits

This package was originally based on the excellent work of @nicolashenry, in jsdom. It has since been pulled out into this separate package.

Dependencies

Dependencies

ID Version
whatwg-encoding ^1.0.5

Development Dependencies

ID Version
eslint ^6.8.0
mocha ^7.0.0

Keywords

encoding html
Details
npm
2026-02-24 13:57:46 +00:00
1
Domenic Denicola
Project Site
MIT
latest
3.7 KiB
Assets (1)
html-encoding-sniffer-2.0.1.tgz 3.7 KiB
Versions (1) View all
2.0.1 2026-02-24