How to check whether a string is a valid HTTP URL?

There are the Uri.IsWellFormedUriString and Uri.TryCreate methods, but they seem to return true for file paths, etc.

How do I check whether a string is a valid (not necessarily active) HTTP URL for input validation purposes?

Try this to validate HTTP URLs (uriName is the URI you want to test):

Uri uriResult;
bool result = Uri.TryCreate(uriName, UriKind.Absolute, out uriResult) 
    && uriResult.Scheme == Uri.UriSchemeHttp;

Or, if you want to accept both HTTP and HTTPS URLs as valid (per J0e3gan's comment):

Uri uriResult;
bool result = Uri.TryCreate(uriName, UriKind.Absolute, out uriResult) 
    && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps);

This method works fine both in http and https. Just one line :)

if (Uri.IsWellFormedUriString("https://www.google.com", UriKind.Absolute))

MSDN: IsWellFormedUriString

    public static bool CheckURLValid(this string source)
    {
        Uri uriResult;
        return Uri.TryCreate(source, UriKind.Absolute, out uriResult) && uriResult.Scheme == Uri.UriSchemeHttp;
    }

Usage:

string url = "htts://adasd.xc.";
if(url.CheckUrlValid())
{
  //valid process
}

UPDATE: (single line of code) Thanks @GoClimbColorado

public static bool CheckURLValid(this string source) => Uri.TryCreate(source, UriKind.Absolute, out Uri uriResult) && uriResult.Scheme == Uri.UriSchemeHttps;

Usage:

string url = "htts://adasd.xc.";
if(url.CheckUrlValid())
{
  //valid process
}

All the answers here either allow URLs with other schemes (e.g., file://, ftp://) or reject human-readable URLs that don't start with http:// or https:// (e.g., www.google.com) which is not good when dealing with user inputs.

Here's how I do it:

public static bool ValidHttpURL(string s, out Uri resultURI)
{
    if (!Regex.IsMatch(s, @"^https?:\/\/", RegexOptions.IgnoreCase))
        s = "http://" + s;

    if (Uri.TryCreate(s, UriKind.Absolute, out resultURI))
        return (resultURI.Scheme == Uri.UriSchemeHttp || 
                resultURI.Scheme == Uri.UriSchemeHttps);

    return false;
}

Usage:

string[] inputs = new[] {
                          "https://www.google.com",
                          "http://www.google.com",
                          "www.google.com",
                          "google.com",
                          "javascript:alert('Hack me!')"
                        };
foreach (string s in inputs)
{
    Uri uriResult;
    bool result = ValidHttpURL(s, out uriResult);
    Console.WriteLine(result + "\t" + uriResult?.AbsoluteUri);
}

Output:

True    https://www.google.com/
True    http://www.google.com/
True    http://www.google.com/
True    http://google.com/
False

How to check whether a string is a valid HTTP URL?

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