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="Banner250x124.gif|113" />
  </query-continue>
  <query>
    <pages>
      <page pageid="838" ns="2" title="Benutzerin:Possi26" />
      <page pageid="3321" ns="0" title="TH:Schatzmeisterei" />
      <page pageid="3500" ns="0" title="Bundestagswahlkreis Eichsfeld – Nordhausen – Unstrut-Hainich-Kreis I" />
      <page pageid="6535" ns="2" title="Benutzer:Käptn Nemo/Enter-Crew/BTW Wahlkampf" />
      <page pageid="9099" ns="2" title="Benutzer:Käptn Nemo/Enter-Crew/BTW Wahlkampf2013" />
      <page pageid="9108" ns="2" title="Benutzer:Käptn Nemo/Enter-Crew/BTW Wahlkampf2017" />
      <page pageid="9140" ns="0" title="TH:AV 2017.1" />
      <page pageid="9214" ns="0" title="TH:LPT2017.1" />
      <page pageid="9282" ns="0" title="TH:LPT2018.1" />
      <page pageid="9305" ns="0" title="TH:AVLTW2019" />
    </pages>
  </query>
</api>