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-continue>
    <allfileusages gafcontinue="Case_sensitive.jpg|216" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Huvudsida" />
      <page pageid="146" ns="0" title="1.3 Checkboxar och radioknappar" />
      <page pageid="371" ns="0" title="Koden till Egen webbläsare" />
      <page pageid="519" ns="0" title="1.7 Funktioner i programmering (DigSkap)" />
      <page pageid="599" ns="0" title="Lektion 16 (DigSkap)" />
      <page pageid="728" ns="0" title="Variablers livslängd &amp; Överskuggning av variabler" />
      <page pageid="758" ns="0" title="3.8 Generiska metoder" />
      <page pageid="911" ns="0" title="LBS gamla kurser (Läsåret 2020-21)" />
    </pages>
  </query>
</api>