Colosseum arena and floor tickets without group tour

[Kenhel]

We are planning our first visit to Rome and staying 3 days pre cruise at the end of August 2024. Our plan is to visit the major sites on our own and not book group tours. We will purchase entry tickets on-line before arrival. For the Colosseum, without a guided tour, can we access the Arena and the Underground as individual visitors? The plan is to purchase tickets at https://ticketing.colosseo.it 90 days prior but the Full Experience tickets with Arena and Floor seem to sell out right away and we are not sure what time the tickets come out (Rome time). 

[BamaBill24]

I looked into this the other day and it looks like they go on sale a month ahead of time.  I think they must sell out super quick due to tour companies buying them.  I am looking to try to snag some for second week in September.  

[rotoal]

I just went through this over the weekend.   The tickets go on sale 30 days ahead of time for the underground tickets or the attic tickets.   I forgot to mark my calendar to start checking until I almost ran out of days that we will be in Rome.  If I hadn't been so determined (stubborn) we wouldn't have had a chance to buy the tickets.   

 

I finally figured out that the tickets go on sale beginning at 9 am Rome time exactly 30 days out, and every 20 minutes or so, the next batch are available.   We have 12:10 PM tickets that I purchased just after 6:30 am East Coast US time, and I have a feeling they were in someone else's shopping basket because they weren't there, and then suddenly they appeared.