EC
ERR_ENCODING_INVALID_ENCODED_DATA
Node.jsERRORNotableEncodingHIGH confidence

Encoded data is invalid for the specified encoding

Production Risk

Can crash HTTP handlers if body decoding fails; use fatal: false for tolerant decoding.

What this means

Thrown when data passed to TextDecoder.decode() is not valid for the specified encoding. For example, passing data with invalid UTF-8 byte sequences when the encoding is set to "utf-8" with fatal mode enabled causes this error.

Why it happens
  1. 1Decoding binary data that contains invalid UTF-8 sequences with fatal mode on
  2. 2Receiving corrupted data from a network source and decoding without error handling
  3. 3Truncated multi-byte UTF-8 character sequences
How to reproduce

Triggered when TextDecoder.decode() encounters invalid bytes and fatal is true.

trigger — this will error
trigger — this will error
const decoder = new TextDecoder('utf-8', { fatal: true });
const invalidUtf8 = Buffer.from([0xff, 0xfe]); // invalid UTF-8
decoder.decode(invalidUtf8); // throws ERR_ENCODING_INVALID_ENCODED_DATA

expected output

TypeError [ERR_ENCODING_INVALID_ENCODED_DATA]: The encoded data was not valid for encoding utf-8

Fix 1

Use fatal: false to replace invalid sequences with the replacement character

WHEN When the input may contain invalid bytes and you want best-effort decoding

Use fatal: false to replace invalid sequences with the replacement character
const decoder = new TextDecoder('utf-8', { fatal: false });
const text = decoder.decode(Buffer.from([0xff, 0xfe]));
// Invalid bytes replaced with U+FFFD (replacement character)

Why this works

fatal: false tells the decoder to substitute invalid sequences with the Unicode replacement character instead of throwing.

Fix 2

Validate and sanitise input before decoding with fatal mode

WHEN When strict validation is required

Validate and sanitise input before decoding with fatal mode
try {
  const text = new TextDecoder('utf-8', { fatal: true }).decode(data);
  return text;
} catch (err) {
  if (err.code === 'ERR_ENCODING_INVALID_ENCODED_DATA') {
    throw new Error('Received invalid UTF-8 data');
  }
  throw err;
}

Why this works

Catching the error allows explicit handling of corrupted encoding.

Code examples
Triggerjs
const decoder = new TextDecoder('utf-8', { fatal: true });
const invalidUtf8 = Buffer.from([0xff, 0xfe]); // invalid UTF-8
decoder.decode(invalidUtf8); // throws ERR_ENCODING_INVALID_ENCODED_DATA  // this triggers ERR_ENCODING_INVALID_ENCODED_DATA
Handle in try/catchjs
try {
  // operation that may throw ERR_ENCODING_INVALID_ENCODED_DATA
  riskyOperation()
} catch (err) {
  if (err.code === 'ERR_ENCODING_INVALID_ENCODED_DATA') {
    console.error('ERR_ENCODING_INVALID_ENCODED_DATA:', err.message)
  } else {
    throw err
  }
}
Defensive pattern to avoid itjs
// Validate inputs before calling the operation
function safe_err_encoding_invalid_encoded_data(...args) {
  // validate args here
  return performOperation(...args)
}
What not to do

✕ Use fatal mode without handling the error for data from external sources

External data may contain invalid sequences; unhandled fatal errors crash the handler.

Sources
Official documentation ↗

Node.js Error Codes Documentation

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