Negate if condition in bash script

You can choose:

if [[ $? -ne 0 ]]; then       # -ne: not equal

if ! [[ $? -eq 0 ]]; then     # -eq: equal

if [[ ! $? -eq 0 ]]; then

! inverts the return of the following expression, respectively.

Better

if ! wget -q --spider --tries=10 --timeout=20 google.com
then
  echo 'Sorry you are Offline'
  exit 1
fi