List of encodings that Node.js supports

I need to read a file which is encoded with ISO-8859-1 (also called latin1), something like this:

var file_contents = fs.readFileSync("test_data.html", "latin1");

However, Node complains about "latin1" or "ISO-8859-1" not being a valid encoding ("Error: Unknown encoding").

What encodings does readFileSync accept?

The encodings are spelled out in the buffer documentation.

Buffers and character encodings:

Character Encodings

• utf8: Multi-byte encoded Unicode characters. Many web pages and other document formats use UTF-8. This is the default character encoding.
• utf16le: Multi-byte encoded Unicode characters. Unlike utf8, each character in the string will be encoded using either 2 or 4 bytes.
• latin1: Latin-1 stands for ISO-8859-1. This character encoding only supports the Unicode characters from U+0000 to U+00FF.

Binary-to-Text Encodings

• base64: Base64 encoding. When creating a Buffer from a string, this encoding will also correctly accept "URL and Filename Safe Alphabet" as specified in RFC 4648, Section 5.
• base64url (Node v14+): base64url encoding as specified in RFC 4648, Section 5. When creating a Buffer from a string, this encoding will also correctly accept regular base64-encoded strings. When encoding a Buffer to a string, this encoding will omit padding.
• hex: Encode each byte as two hexadecimal characters.

Legacy Character Encodings

• ascii: For 7-bit ASCII data only. Generally, there should be no reason to use this encoding, as 'utf8' (or, if the data is known to always be ASCII-only, 'latin1') will be a better choice when encoding or decoding ASCII-only text.
• binary: Alias for 'latin1'.
• ucs2: Alias of 'utf16le'.