How to find out how full a flight is on average?

Factual Questions
1

going to Alaska next week on a Delta 767 from Atlanta I hope it’s not too full. Can’t find this online but maybe the airlines consider it a trade secret.

2

There is a website called ExpertFlyer that has this information. Very frequent fliers use it all the time. However, there are some caveats:

  1. It costs money to use all its features.
  2. It will only tell you how many seats are left in any fare class if there are less than 7. In other words, if you see 4 seats left, that is true. If you see 7, that means there are at least 7. This is because the exact number of seats available in each class is proprietary.
3

pretty full flight. I guess there are not many flights to alaska so that’s not a surprise

4

Out of curiosity, why is the fullness of a flight of concern? COVID? Carry-on luggage? Something else?

5

mostly Covid

6

Now that the question is answered, this is anecdotal, but I have flown about a dozen times in the last couple of months and every single flight has been very full. I believe the airlines are not back to full schedules due to staffing issues, and there are a lot of people flying.