diff --git a/web/site/instances.php b/web/site/instances.php
index bacdf60..1369553 100644
--- a/web/site/instances.php
+++ b/web/site/instances.php
@@ -330,6 +330,8 @@ $order=array(
 	'tusersa'=>array('t'=>_('By number of users, ascending'),'q'=>'Instances.UserCount ASC'),
 	'ausersd'=>array('t'=>_('By number of active users, descending'),'q'=>'Instances.ActiveUsersMonth DESC'),
 	'ausersa'=>array('t'=>_('By number of active users, ascending'),'q'=>'Instances.ActiveUsersMonth ASC'),
+	'checksd'=>array('t'=>_('By responsiveness to our checks, descending'),'q'=>'(Instances.OkChecks / Instances.TotChecks) DESC, Instances.TotChecks DESC'),
+	'checksa'=>array('t'=>_('By responsiveness to our checks, ascending'),'q'=>'(Instances.OkChecks / Instances.TotChecks) ASC, Instances.TotChecks ASC'),
 	'charsd'=>array('t'=>_('By maximum number of characters per toot, descending'),'q'=>'Instances.MaxTootChars DESC'),
 //	'charsa'=>array('t'=>_('By maximum number of characters per toot, ascending'),'q'=>'Instances.MaxTootChars ASC'),
 	'noxd'=>array('t'=>_('Noxious first (switches off “Exclude noxious”)'),'q'=>'Instances.Noxious DESC')
@@ -671,6 +673,7 @@ while ($if<$il && $row=mysqli_fetch_assoc($res)) {
 		$out.='>'.ldate($buf[$i]['Time']).'</td>';
 	}
 	$out.='</tr></table>'.N;
+	$out.='<div class="dida100">'._('Succesful checks').': '.$row['OkChecks'].'/'.$row['TotChecks'].' ('.round(100 / $row['TotChecks'] * $row['OkChecks'], 2).'%)</div>'.N;
 
 	$out.='</div></div>'.N;