Note: This feature is available in Web Workers.
The fatal read-only property of the TextDecoder interface is a Boolean indicating whether the error mode is fatal.
If the property is true, then a decoder will throw a TypeError if it encounters malformed data while decoding. If false, the decoder will substitute the invalid data with the replacement character U+FFFD (�). The value of the property is set in the fatal argument to the decoder's constructor.
A boolean which will be true if the error mode is set to fatal. Otherwise, it will be false, indicating that the error mode is replacement.