 <p>Note I'm assuming you <em>just</em> have the data part of the string, not an entire JSON fragment - i.e.</p> <pre><code>string s = @"blah \u003c blah \u00252 blah"; </code></pre> <p>If the above assumption is wrong and you have a full JSON fragment, just use <code>JavaScriptSerializer</code> to get an object from the data.</p> <p>Annoyingly, <code>HttpUtility</code> has encode but not decode. </p> <p>You could spoof the string into a full JSON object, though - this seems a bit overkill:</p> <pre><code>class Dummy { public string foo { get; set; } } static void Main(string[] args) { string s = @"blah \u003c blah \u00252 blah"; string json = @"{""foo"":""" + s + @"""}"; string unencoded = new JavaScriptSerializer().Deserialize&lt;Dummy&gt;(json).foo; } </code></pre>