There are two factories of HexFormat with preset parameters of() and ofDelimiter(delimiter). For other parameter combinations the withXXX methods return copies of HexFormat modified withPrefix(String), withSuffix(String), withDelimiter(String) or choice of withUpperCase() or withLowerCase() parameters.

For primitive to hexadecimal string conversions the toHexDigits methods include toHexDigits(byte), toHexDigits(int), and toHexDigits(long), etc. The default is to use lowercase characters "0-9","a-f". For conversions producing uppercase hexadecimal the characters are "0-9","A-F". Only the HexFormat.isUpperCase() parameter is considered; the delimiter, prefix and suffix are not used.

For hexadecimal string to primitive conversions the fromHexDigits methods include fromHexDigits(string), fromHexDigitsToLong(string), and fromHexDigit(int) converts a single character or codepoint. For conversions from hexadecimal characters the digits and uppercase and lowercase characters in "0-9", "a-f", and "A-F" are converted to corresponding values 0-15. The delimiter, prefix, suffix, and uppercase parameters are not used.

For byte array to formatted hexadecimal string conversions the formatHex methods include formatHex(byte[]) and formatHex(Appendable, byte[]). The formatted output is a string or is appended to an Appendable such as StringBuilder or PrintStream. Each byte value is formatted as the prefix, two hexadecimal characters from the uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last. For conversions producing uppercase hexadecimal strings use withUpperCase().

For formatted hexadecimal string to byte array conversions the parseHex methods include parseHex(CharSequence) and parseHex(char[], offset, length). Each byte value is parsed from the prefix, two case insensitive hexadecimal characters, and the suffix. A delimiter follows each formatted value, except the last.