We bought our tickets through an app on the phone it was quick and simple

I bought my tickets there and on he day and had no problem!!

WE just walked right in and had a lovely tour. There were only about eight of us on the tour but it was at the end of the day...and it was raining so a perfect thing to do! ;-)

We got tickets when we got there and wasn't a problem but if you are going to the Guinness brewery definitely get skip the line tickets.

We bought ours ahead of time on line, but it seemed like there were tour slots happening every half hour or hour, and buying tickets there seemed like it would probably be fine.

We walked right in an were four of about eight people on the tour. It was a Saturday at around noon. Don't think there is a concern about getting in and the tours run I think every half hour. You can pay an up charge to be able to 13 euros to taste all three beers, the red (original), blonde, and pale ale, it tuns out to be a little more than a pint. For me I only like the original so I chose the reg price that included a pint of one of the three. Have fun!