You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information.
<?xml version="1.0"?>
<api>
  <query>
    <allredirects>
      <r ns="0" title="Bifrost (アレンジ)" />
      <r ns="0" title="Information" />
      <r ns="0" title="Life of Eorzea" />
      <r ns="0" title="SIGMA Because" />
      <r ns="0" title="Shilverlight Wings -時を渡る翼-" />
      <r ns="0" title="Work" />
      <r ns="0" title="コミックマーケットC78" />
      <r ns="0" title="コミックマーケットC79" />
      <r ns="0" title="楽曲使用ガイダンス" />
      <r ns="0" title="潮鳴り -in the lights-" />
    </allredirects>
  </query>
</api>