Arab media are reporting that some half a million people are expected to go to the Temple Mount today, the last Friday of Ramadan. Similarly, they reported that over 400,000 people came to the courtyard on the night of Laylat al-Qadr earlier this week.
The Temple Mount is about 35 acres (14 hectares); this number would be reduced by the many structures on it where people cannot stand.
Approximately 5000 people can fit in an acre assuming one square yard (meter) per person. Certainly you can jam pack more in that space but not if they want to kneel and prostrate themselves, which the Muslims do in prayer.
Here's a photo from last Friday when the number of worshipers was estimated at "250,000," showing how much space is between them:
So at no time can the Temple Mount support more than 150,000 people, and probably the number is significantly lower than that.
I supposed it is possible that people are not staying the entire time, but I'm not sure.
However, it seems likely that the figure of half a million visiting the Al Aqsa Mosque today is a very large exaggeration.