title: Node Express Content-Length
body: <p>I use node.js and express at a small project. I set response header like blow:   </p>
  
  <pre><code>res.set({'Content-Type':'text/plain;charset=utf-8',    
  'Content-Length': Buffer.byteLength(data, 'utf-8')});       
  </code></pre>
  
  <p>I can use <code>console.log</code> print data's length is 317.    </p>
  
  <p>But at browser's console, I just get these:   </p>
  
  <blockquote>
    <p>Connection:keep-alive<br>
    Content-Encoding:gzip<br>
    Content-Type:text/plain;charset=utf-8<br>
    Date:Sat, 01 Jun 2013 08:21:59 GMT<br>
    Transfer-Encoding:chunked<br>
    Vary:Accept-Encoding<br>
    X-Powered-By:Express   </p>
  </blockquote>
  
  <p>So, why the <strong><em>content-length</em></strong> disappeared?</p>