Using symbolic references, the code you've written can be reduced as follows and this will also work faster.

@tags = qw[body title h1 h2 h3 h4 h5 h6 li p a];
@attributes = qw[alt href];

foreach $tag (@tags) {
    $$tag++ while ($html =~ /<$tag.*?>.*?\b$WHATWANT{'term'}'?s?\b.*?<
+\/$tag>/gis);
}

foreach $attribute (@attributes) {
    $$attribute++ while ($html =~ /(alt|href)=["'].*?\b$WHATWANT{'term
+'}'?s?\b.*?["']/gis);
}
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Mani.