Note that Seatcounter etc. will show the number of tickets the airline is willing to sell, not the actual number of seats remaining. The tickets for sale includes overbooking, so they may still show 5 tickets for sale on a flight with 149 out 150 seats full. The airline is counting on 4 or more people not showing up.

Likewise, seat maps show reserved seats, but also block out some seats that aren't reserved and don't show people who have tickets but no seat assignment yet.