<p>How can you convert a byte array to a hexadecimal string and vice versa?</p>

You can use
```
Convert.ToHexString
```
starting with .NET 5.
There's also a method for the reverse operation:
```
Convert.FromHexString
```
.
For older versions of .NET you can either use:
```
```
public static string ByteArrayToString(byte[] ba)
{
  StringBuilder hex = new StringBuilder(ba.Length * 2);
  foreach (byte b in ba)
    hex.AppendFormat("{0:x2}", b);
  return hex.ToString();
}
```
```
or:
```
```
public static string ByteArrayToString(byte[] ba)
{
  return BitConverter.ToString(ba).Replace("-","");
}
```
```
There are even more variants of doing it, for example
here
.
The reverse conversion would go like this:
```
```
public static byte[] StringToByteArray(String hex)
{
  int NumberChars = hex.Length;
  byte[] bytes = new byte[NumberChars / 2];
  for (int i = 0; i < NumberChars; i += 2)
    bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
  return bytes;
}
```
```
Using
```
Substring
```
is the best option in combination with
```
Convert.ToByte
```
. See
this answer
for more information. If you need better performance, you must avoid
```
Convert.ToByte
```
before you can drop
```
SubString
```
.