Tumblr Manual Installation Instructions

For displaying Disqus on your site, typically on individual article or post pages.

In Tumblr, visit Settings > Your Site > Customize
Select "Edit HTML".
Copy and paste the following code anywhere between the <head> and </head> tags: <meta name='text:Disqus Shortname' content='' />

Copy and paste the following code immediately after {/block:Posts}:

{block:IfDisqusShortname}

<div id="disqus_thread"></div>
<script type="text/javascript">
    /* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
    var disqus_shortname = '<example>'; // Required - Replace example with your forum shortname

    /* * * DON'T EDIT BELOW THIS LINE * * */
    (function() {
        var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
        dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
        (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
    })();
</script>
<noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript>
<a href="http://disqus.com" class="dsq-brlink">blog comments powered by <span class="logo-disqus">Disqus</span></a>

{/block:IfDisqusShortname}

Update the disqus_shortname variable in the embed code provided. If you don't, Disqus won't work.
Select "Update Preview" and then "Save"
Select "Appearance"
Enter your Disqus site shortname in the "Disqus Shortname" field

Comment count code

For displaying comment counts on your site's home page.

In Tumblr, visit Settings > Your Site > Customize
Select "Edit HTML".
Copy and paste the following code immediately before {/block:Posts}:

{block:IndexPage}<a class="dsq-comment-count" href="{Permalink}#disqus_thread">Comments</a>
<script type="text/javascript">
    var disqus_shortname = '{text:Disqus Shortname}';

    (function () {
        var s = document.createElement('script'); s.async = true;
        s.type = 'text/javascript';
        s.src = '//' + disqus_shortname + '.disqus.com/count.js';
        (document.getElementsByTagName('HEAD')[0] || document.getElementsByTagName('BODY')[0]).appendChild(s);
    }());
</script>
{/block:IndexPage}