diff --git a/bin/log-defer-viz b/bin/log-defer-viz
index bbae3fb..3595c06 100755
--- a/bin/log-defer-viz
+++ b/bin/log-defer-viz
@@ -22,7 +22,7 @@ my $colour_spec = {
 
 my @opt_spec = (
   ## INPUT FORMAT
- 
+
   'input-format=s',
 
   ## DATE
@@ -55,6 +55,7 @@ my @opt_spec = (
   'data!',
   'data-format=s',
   'data-only',
+  'count=s@',
 
   ## MISC
 
@@ -115,6 +116,7 @@ if ($opt->{'data-only'}) {
   $opt->{data} = 1;
 }
 
+my $count = {} if exists $opt->{count};
 
 my $columns = $opt->{'timer-columns'};
 
@@ -169,6 +171,10 @@ while (my $file = shift) {
   close($fh);
 }
 
+if (scalar @{$opt->{count}}) {
+  print "  Count:\n";
+  print output_data($count);
+}
 
 
 sub handle_entry {
@@ -270,7 +276,7 @@ sub handle_entry {
 
     print "  |_" . format_time_offset($entry->{end}) . " [END]\n\n";
   }
-  
+
   if ($opt->{timers}) {
     print Log::Defer::Viz::render_timers(width => $columns-10, timers => $entry->{timers}) if $entry->{timers};
   }
@@ -283,6 +289,15 @@ sub handle_entry {
       print "  ** This log has associated data. See it with --data\n"
         unless $opt->{quiet} || (defined $opt->{data} && !$opt->{data});
     }
+
+    foreach my $key (@{ $opt->{count} }) {
+      if (!exists $count->{$key}) {
+        $count->{$key} = {};
+      }
+      if (exists $entry->{data}->{$key}) {
+        $count->{$key}->{$entry->{data}->{$key}} += 1;
+      }
+    }
   }
 
   print "\n";
@@ -432,6 +447,13 @@ Data is extra embedded information in the log file. The available outputs are C<
     $ log-defer-viz --data-format=dumper  ## Data::Dumper
     $ log-defer-viz --data-only  ## only show data
 
+=head1 COUNT
+
+The count parameter provides a method to count the number of times a specific key/value appears in the data section of the log file.
+
+    $ log-defer-viz --data --count ip_address ## Display how many log lines for each ip address
+    $ log-defer-viz --data --count ip_address --count user_id ## Display how many log lines for each ip address and each user_id
+
 =head1 MISC
 
     $ log-defer-viz --help  ## the text you're reading now