diff -u b/modules/redirect_404/redirect_404.module b/modules/redirect_404/redirect_404.module
--- b/modules/redirect_404/redirect_404.module
+++ b/modules/redirect_404/redirect_404.module
@@ -48,7 +48,6 @@
   if ($row_limit > 0) {
     $query = \Drupal::database()->select('redirect_404', 'r404')
       ->extend('Drupal\Core\Database\Query\TableSortExtender')
-      ->orderBy('count', 'DESC')
       ->orderBy('timestamp', 'DESC')
       ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
       ->limit($row_limit - 1)
diff -u b/modules/redirect_404/src/EventSubscriber/Redirect404Subscriber.php b/modules/redirect_404/src/EventSubscriber/Redirect404Subscriber.php
--- b/modules/redirect_404/src/EventSubscriber/Redirect404Subscriber.php
+++ b/modules/redirect_404/src/EventSubscriber/Redirect404Subscriber.php
@@ -75,6 +75,7 @@
       $langcode = $this->languageManager->getCurrentLanguage()->getId();
       $this->redirectStorage->logRequest($path, $langcode);
     }
+    debug($this->redirectStorage->purgeOldRequests());
   }
 
 }
diff -u b/modules/redirect_404/src/RedirectNotFoundStorage.php b/modules/redirect_404/src/RedirectNotFoundStorage.php
--- b/modules/redirect_404/src/RedirectNotFoundStorage.php
+++ b/modules/redirect_404/src/RedirectNotFoundStorage.php
@@ -70,6 +70,32 @@
       ->execute();
   }
 
+  public function purgeOldRequests() {
+    // Cleanup the redirect_404 table.
+    $row_limit = \Drupal::config('redirect_404.settings')->get('row_limit');
+
+    // For row limit n, get the wid of the nth row in descending wid order.
+    // Counting the most recent n rows avoids issues with wid number sequences,
+    // e.g. auto_increment value > 1 or rows deleted directly from the table.
+    $query = $this->database->select('redirect_404', 'r404');
+    //$query->fields('r404');
+    $query->addExpression('pow(2, -(UNIX_TIMESTAMP(NOW()) - timestamp)/86400)', 'boh');
+    //$query->condition('relevancy', 0.99, '>');
+    $query->orderBy('boh', 'DESC');
+
+    $query->fields('r404');
+    $query->condition('relevancy', 0.99, '>');
+    $result = $query->execute()->fetchAll();
+
+    if ($result) {
+      $delete = $this->database->select('redirect_404', 'r404');
+      $delete->condition('path', $result, 'NOT IN');
+      $result = $delete->execute()->fetchAll();
+    }
+
+    return $result;
+  }
+
   /**
    * {@inheritdoc}
    */
diff -u b/modules/redirect_404/src/RedirectNotFoundStorageInterface.php b/modules/redirect_404/src/RedirectNotFoundStorageInterface.php
--- b/modules/redirect_404/src/RedirectNotFoundStorageInterface.php
+++ b/modules/redirect_404/src/RedirectNotFoundStorageInterface.php
@@ -47,2 +47,4 @@
 
+  public function purgeOldRequests();
+
 }