This entry is part 15 of 19 in the Bash-whacking series
echo "Size WITHOUT accepting gzip"
curl http://www.supermind.org --silent --write-out "size_download=%{size_download}\n" --output /dev/null
echo "Size WITH accepting gzip"
curl http://www.supermind.org --silent -H "Accept-Encoding: gzip,deflate"  --write-out "size_download=%{size_download}\n" --output /dev/null

You can of course substitute the URL with a different one.

On my site, this is what I get:

$curl http://www.supermind.org --silent --write-out "size_download=%{size_download}\n" --output /dev/null
$size_download=10560
$curl http://www.supermind.org --silent -H "Accept-Encoding: gzip,deflate"  --write-out "size_download=%{size_download}\n" --output /dev/null
$size_download=4345