How to get the Youtube VideoId from Url in C# and VB.NET

To get the Youtube VideoId from an Url in C# and VB.NET you can use the following snippet.
It matches these 18 type of Youtube Links (Sample Data):

Sample Input

Sample C#

using System.Linq;
using System.Text.RegularExpressions;

namespace de.fesslersoft.YoutubeRegexTest
{
    internal static class Youtube
    {
        private const string YoutubeLinkRegex = "(?:.+?)?(?:\\/v\\/|watch\\/|\\?v=|\\&v=|youtu\\.be\\/|\\/v=|^youtu\\.be\\/)([a-zA-Z0-9_-]{11})+";

        internal static string GetVideoId(string input)
        {
            var regex = new Regex(YoutubeLinkRegex, RegexOptions.Compiled);
            foreach (Match match in regex.Matches(input))
            {
                //Console.WriteLine(match);
                foreach (var groupdata in match.Groups.Cast<Group>().Where(groupdata => !groupdata.ToString().StartsWith("http://") && !groupdata.ToString().StartsWith("https://") && !groupdata.ToString().StartsWith("youtu") && !groupdata.ToString().StartsWith("www.")))
                {
                    return groupdata.ToString();
                }
            }
            return string.Empty;
        }
    }
}

Sample VB.NET

Imports System.Linq
Imports System.Text.RegularExpressions
 
Namespace de.fesslersoft.YoutubeRegexTest
    Friend NotInheritable Class Youtube
        Private Sub New()
        End Sub
        Private Const YoutubeLinkRegex As String = "(?:.+?)?(?:\/v\/|watch\/|\?v=|\&v=|youtu\.be\/|\/v=|^youtu\.be\/)([a-zA-Z0-9_-]{11})+"
 
        Friend Shared Function GetVideoId(input As String) As String
            Dim regex = New Regex(YoutubeLinkRegex, RegexOptions.Compiled)
            For Each match As Match In regex.Matches(input)
                For Each data As Group In match.Groups.Cast(Of Group)().Where(Function(groupdata) Not groupdata.ToString().StartsWith("http://") AndAlso Not groupdata.ToString().StartsWith("https://") AndAlso Not groupdata.ToString().StartsWith("youtu") AndAlso Not groupdata.ToString().StartsWith("www."))
                    Return data.ToString()
                Next
            Next
            Return String.Empty
        End Function
    End Class
End Namespace

Output / Sample

var urlList = new List<String>
{
	"http://youtu.be/AAAAAAAAA01",
	"http://www.youtube.com/embed/watch?feature=player_embedded&v=AAAAAAAAA02",
	"http://www.youtube.com/embed/watch?v=AAAAAAAAA03",
	"http://www.youtube.com/embed/v=AAAAAAAAA04",
	"http://www.youtube.com/watch?feature=player_embedded&v=AAAAAAAAA05",
	"http://www.youtube.com/watch?v=AAAAAAAAA06",
	"www.youtube.com/watch?v=AAAAAAAAA07",
	"www.youtu.be/AAAAAAAAA08",
	"youtu.be/AAAAAAAAA09",
	"youtube.com/watch?v=AAAAAAAAA10",
	"http://www.youtube.com/watch/AAAAAAAAA11",
	"http://www.youtube.com/v/AAAAAAAAA12",
	"http://www.youtube.com/v/AAAAAAAAA13",
	"http://www.youtube.com/watch?v=i-AAAAAAA14&feature=related",
	"http://www.youtube.com/attribution_link?u=/watch?v=AAAAAAAAA15&feature=share&a=9QlmP1yvjcllp0h3l0NwuA",
	"http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&u=/watch?v=AAAAAAAAA16&feature=em-uploademail",
	"http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&feature=em-uploademail&u=/watch?v=AAAAAAAAA17",
	"http://www.youtube.com/v/A-AAAAAAA18?fs=1&rel=0"
};

foreach (var entry in urlList)
{
	Console.WriteLine(Youtube.GetVideoId(entry));
}
Console.Read();

will result in the follwing output:

A simpler but less matching solution can be found here: How to get the VideoID of a youtube video using Regex