How to convert byte array to a hexadecimal string in C#, and vice versa?

To convert byte array to hexadecimal string in C# use the following methods.

1. Using C# 5 Convert.ToHexString() method
2. Using C# StringBuilder and AppendFormat
3. Using C# BitConverter.ToString() method

Using C# 5 Convert.ToHexString() method #

If you are using C# 5 version you can make use of Convert.ToHexString() method to convert byte array to hexadecimal string.

string result = Convert.ToHexString(bytesToConvert);

This is the fastest way to convert a byte array to hexadecimal string in C# and also it’s very clean and simple method.

If you are using older versions of C# .Net use the below methods.

Using C# StringBuilder and AppendFormat #

We can loop through the byte array and append it to a string builder to convert byte array to hexadecimal string as shown below.

public static string ByteArrayToHexadecimalString(byte[] byteArray)
{
  StringBuilder hexadecimalString = new StringBuilder(byteArray.Length * 2);
  foreach (byte b in byteArray){
     hexadecimalString.AppendFormat("{0:x2}", b);
  }
  return hexadecimalString.ToString();
}

Using C# BitConverter.ToString() method #

Another way is to use C# BitConverter.ToString() method, through which we can directly convert C# byte array to hexadecimal string.

public static string ByteArrayToHexadecimalString(byte[] byteArray)
{
  return BitConverter.ToString(byteArray).Replace("-","");
}

Convert Hexadecimal string to byte array in C# #

Similarly to convert hexadecimal string to byte array we can use Convert.FromHexString() method in C# 5.

var result = Convert.FromHexString(hexadecimalstring);

In the older versions of C# .Net use the below method.

public static byte[] HexadecimalStringToByteArray(String hexadecimalString)
{
  int length = hexadecimalString.Length;
  byte[] byteArray = new byte[length / 2];
  for (int i = 0; i < length; i += 2){
    byteArray[i / 2] = Convert.ToByte(hexadecimalString.Substring(i, 2), 16);
  }
  return byteArray;
}