Convert string to hex-string in C#

Question

I have a string like "sample". I want to get a string of it in hex format; like this:

"796173767265"

Please give the C# syntax.

Which hex format are you talking about? ASCII? (The example you give is not ASCII for "sample"; is that a reference address?) Little endian, or big? What size? — jpaugh
– jpaugh, Commented Jun 8, 2013 at 12:40
stackoverflow.com/a/65508621/532647 the not-most-upvoted answer has a built-in .NET 5 helper, linking from here for more visibility — Iarek
– Iarek, Commented Jun 10, 2021 at 13:47

T.S. · Accepted Answer · 2014-02-05 03:34:21Z

195

First you'll need to get it into a byte[], so do this:

byte[] ba = Encoding.Default.GetBytes("sample");

and then you can get the string:

var hexString = BitConverter.ToString(ba);

now, that's going to return a string with dashes (-) in it so you can then simply use this:

hexString = hexString.Replace("-", "");

to get rid of those if you want.

NOTE: you could use a different Encoding if you needed to.

edited Feb 5, 2014 at 3:34

T.S.

19.6k11 gold badges70 silver badges96 bronze badges

answered Jun 8, 2013 at 12:41

Mike Perrenoud

68.1k32 gold badges167 silver badges238 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

jacktric Over a year ago

Using the Default Encoding could fail in any case? Running on different versions of Windows for example?

Mike Perrenoud Over a year ago

@jacktric if you know the encoding you should always use the specific encoding. However, I've been using the Default encoding for more than a decade and haven't had issues in production across geographic locations or versions of Windows.

CCG Over a year ago

What if you want it to go the other way around? So from a variable which is a string in hex to a string with only alphanumerals?

Martin Costello · Accepted Answer · 2020-12-30 14:52:28Z

59

In .NET 5.0 and later you can use the Convert.ToHexString() method.

using System;
using System.Text;

string value = "Hello world";

byte[] bytes = Encoding.UTF8.GetBytes(value);

string hexString = Convert.ToHexString(bytes);

Console.WriteLine($"String value: \"{value}\"");
Console.WriteLine($"   Hex value: \"{hexString}\"");

Running the above example code, you would get the following output:

String value: "Hello world"
   Hex value: "48656C6C6F20776F726C64"

edited Dec 30, 2020 at 14:52

answered Dec 30, 2020 at 14:33

Martin Costello

11.1k5 gold badges66 silver badges78 bronze badges

1 Comment

Momoro Over a year ago

Great answer, I didn't know .NET had finally included a built-in way to convert strings to hex! (Not just Base64!) Thanks!

franckspike · Accepted Answer · 2014-12-08 17:26:55Z

33

For Unicode support:

public class HexadecimalEncoding
{
    public static string ToHexString(string str)
    {
        var sb = new StringBuilder();

        var bytes = Encoding.Unicode.GetBytes(str);
        foreach (var t in bytes)
        {
            sb.Append(t.ToString("X2"));
        }

        return sb.ToString(); // returns: "48656C6C6F20776F726C64" for "Hello world"
    }

    public static string FromHexString(string hexString)
    {
        var bytes = new byte[hexString.Length / 2];
        for (var i = 0; i < bytes.Length; i++)
        {
            bytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
        }

        return Encoding.Unicode.GetString(bytes); // returns: "Hello world" for "48656C6C6F20776F726C64"
    }
}

answered Dec 8, 2014 at 17:26

franckspike

2,31426 silver badges19 bronze badges

1 Comment

pylover Over a year ago

Its better to use two Extension Methods for that

svick · Accepted Answer · 2013-06-09 15:37:27Z

27

var result = string.Join("", input.Select(c => ((int)c).ToString("X2")));

OR

var result  =string.Join("", 
                input.Select(c=> String.Format("{0:X2}", Convert.ToInt32(c))));

edited Jun 9, 2013 at 15:37

svick

247k54 gold badges405 silver badges535 bronze badges

answered Jun 8, 2013 at 12:48

Damith

63.2k13 gold badges105 silver badges154 bronze badges

4 Comments

svick Over a year ago

You could simplify that to ((int)c).ToString("X").

svick Over a year ago

Actually, I realized this would be wrong for any characters ≤ 0x0F, because of the missing zero padding. To fix that, use ToString("X2").

Piotr Kula Over a year ago

The first one worked for me on dot42 it takes about 10 seconds to process 4096bytes but I needed it for debugging and it worked as opposed to the BitConverter that just hangs. +1

dbc Jul 31 at 0:27

The advantage of this answer over others is that the conversion is done without an Encoding, so if there are any char values that represent invalid Unicode code points they will get preserved and shown rather than replaced with a fallback.

fubo · Accepted Answer · 2022-07-15 05:43:11Z

16

According to this snippet here, this approach should be good for long strings:

private string StringToHex(string hexstring)
{
    StringBuilder sb = new StringBuilder();
    foreach (char t in hexstring)
    { 
        //Note: X for upper, x for lower case letters
        sb.Append(Convert.ToInt32(t).ToString("x2")); 
    }
    return sb.ToString();
}

usage:

string result = StringToHex("Hello world"); //returns "48656c6c6f20776f726c64"

Another approach in one line

string input = "Hello world";
string result = String.Concat(input.Select(x => ((int)x).ToString("x2")));

edited Jul 15, 2022 at 5:43

answered Sep 3, 2014 at 7:51

fubo

46.2k20 gold badges109 silver badges139 bronze badges

1 Comment

M.M Over a year ago

It should be "x2" or "X2" otherwise leading 0 is omitted from each byte

Slai · Accepted Answer · 2019-11-20 08:15:06Z

7

few Unicode alternatives

var s = "0𝟏𝟚𝟥𝟰𝟻";

var s1 = string.Concat(s.Select(c => $"{(int)c:x4}"));  // left padded with 0 - "0030d835dfcfd835dfdad835dfe5d835dff0d835dffb"

var sL = BitConverter.ToString(Encoding.Unicode.GetBytes(s)).Replace("-", "");       // Little Endian "300035D8CFDF35D8DADF35D8E5DF35D8F0DF35D8FBDF"
var sB = BitConverter.ToString(Encoding.BigEndianUnicode.GetBytes(s)).Replace("-", ""); // Big Endian "0030D835DFCFD835DFDAD835DFE5D835DFF0D835DFFB"

// no encodding "300035D8CFDF35D8DADF35D8E5DF35D8F0DF35D8FBDF"
byte[] b = new byte[s.Length * sizeof(char)];
Buffer.BlockCopy(s.ToCharArray(), 0, b, 0, b.Length);
var sb = BitConverter.ToString(b).Replace("-", "");

edited Nov 20, 2019 at 8:15

answered Aug 22, 2016 at 18:58

Slai

23k5 gold badges49 silver badges55 bronze badges

Comments

flodis · Accepted Answer · 2022-05-16 08:57:21Z

0

In case detailed conversion with regard to endianness of bytes or words is required, here is an example of the craft to do bitwise conversion.

var bcd = new byte[] { 64, 7, 19, 0, 0, 0 };
var str = String.Join("", bcd.Reverse().Select(b => $"{b:X2}"));

str => 000000317004

To also swap 4-bit nibbles of each byte, shift and mask to format each 4 bit separately.

var bcd = new byte[] { 64, 7, 19, 0, 0, 0 };
var str = String.Join("", bcd.Reverse().Select(b => $"{b & 0x0F:X1}{b>>4:X1}"));

str => 000000130740

edited May 16, 2022 at 8:57

answered Nov 5, 2021 at 18:25

flodis

1,27115 silver badges9 bronze badges

1 Comment

robnick Over a year ago

This answer doesn't appear to have anything to do with the question?

user13776577 · Accepted Answer · 2024-03-01 04:45:24Z

0

Convert it to number, use the toString("X") method to convert it to hex.

long.TryParse("796173767265", out long number);
Console.WriteLine(number.ToString("X"));

// output: B95FA79261

answered Mar 1, 2024 at 4:45

user13776577

Collectives™ on Stack Overflow

Convert string to hex-string in C#

8 Answers 8

3 Comments

1 Comment

1 Comment

4 Comments

1 Comment

Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

8 Answers 8

3 Comments

1 Comment

1 Comment

4 Comments

1 Comment

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related