You might look at HTML::Parser instead of rolling your own.

Failing that, you might try combining many of these into one search, so you're not looping through the data so much. Maybe something like:

while ($html =~ /<(\w+).*?>\b$WHATWANT{'term'}?s?\b.*?</\1>/gis) {
  my $tag = $1;
  $tag =~ tr/A-Z/a-z/;
  if ($tag eq 'title') {
  }
  elsif ($tag eq 'h1') {
#....
}
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Your two patterns for single quote vs double quote could be reduced to one, like

while ($html =~ /href=(['"]).*?$WHATWANT{'term'}'?s?.*?\1/gis) { $term
+shref++; } ## End while
[download]