HttpEncoder.UrlEncode Method (Byte(), Int32, Int32)

.NET Framework (current version)

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Encodes an array of characters that are not allowed in a URL into a hexadecimal character-entity equivalent.

Namespace:   System.Web.Util
Assembly:  System.Web (in System.Web.dll)

Protected Friend Overridable Function UrlEncode (
	bytes As Byte(),
	offset As Integer,
	count As Integer
) As Byte()


Type: System.Byte()

An array of bytes to encode.

Type: System.Int32

The position in the bytes array at which to begin encoding.

Type: System.Int32

The number of items in the bytes array to encode.

Return Value

Type: System.Byte()

An array of encoded characters.

Exception Condition

offset is less than zero or greater than the length of the bytes array.


count is less than zero or count plus offset is greater than the length of the bytes array.


bytes is null.

The UrlEncode method is called by several URL encoding methods in the HttpUtility class.

The UrlEncode method URL-encodes any character that is not in the set of ASCII characters that is considered to be URL-safe. Spaces are encoded as the ASCII "+" character. URL-safe ASCII characters include the ASCI characters (A to Z and a to z), numerals (0 to 9), and some punctuation marks. The following table lists the punctuation marks that are considered URL-safe ASCII characters.








Period (dot)


Exclamation mark


Asterisk (star)


Opening parenthesis


Closing parenthesis

.NET Framework
Available since 4.0
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