Notre Dame It is now May 2 Any changes to ticketing?

Just my recent experience: I visited Notre Dame Monday April 28 at about 1:00-1:30. I did not have timed tickets; they were sold out when I checked 1 & 2 days before. So I just got in the line for those who did not have timed tickets. It moved pretty fast and I was in the cathedral in about 20 minutes.
It’s up to you to attend services, and do try to get tickets for your required dates. But if you can’t, waiting in line a while is certainly worth it.

Hi mld780!

Reservations are not required, but I would strongly recommend reserving a time siot in advance, or else you could have a long wait time (over an hour), especially like you said, we're coming into peak season. Notre Dame has a very strict capacity limit and those without reservations are the lowest priority, and are not guaranteed entrance.

• The first batch of new time slots is released at midnight (Paris time), for the date 2 days ahead. For example: At midnight (Paris time) on July 1st, time slots are released for July 3rd. Any dates beyond July 3rd will automatically be greyed out/appear to be full. This first batch can fill up within ~20 minutes of being released, so I recommend opening the reservation system around 11:50pm. For the fastest connection, I recommend accessing it on your computer using Chrome.
• A second batch of new/additional "same day" time slots are released 4 hours in advance. For example: At 5:00am (Paris time), new time slots are released for 9:00am for that same day. At 5:30am, new time slots are released for 9:30am, etc. However, there are certain hours when no time slots are ever offered, therefore no new time slots are released 4 hours in advance of those hours. For example: No time slots are offered for 12:00pm, therefore no new time slots will be released at 8:00am. The availability of these time slots is based on the planned and/or current capacity available inside the cathedral, and are not guaranteed.

Time slots are offered in 15 minute intervals. This is meant to help spread out the flow of visitors coming in/out, but it doesn't mean that you're limited to only 15 minutes to visit!

• Monday to Friday, time slots are generally offered between 9:00am and 11:00am and between 1:00pm and 4:00pm. On Thursday, additional time slots are generally offered between 7:00pm and 9:00pm.
• On Sunday, time slots are generally offered between 1:00pm and 3:00pm.

Not every time slot will be offered every day. Pilgrim groups, school groups, international diplomats/government officials, etc. book their time slots/reservations on a different reservation system and/or with Notre Dame's management team directly. Due to Notre Dame's capacity limit, if a large group is expected, no time slots/reservations for visitors will be offered for that day/time. For example, if there's a group of 2,000 pilgrims scheduled to visit on July 3rd at 9:00am, no visitor time slots will be offered for 9:00am that day (or within an hour or 2 afterwards)

No time slots are offered during Mass times. Visitors are still allowed to enter during Mass by waiting in the "Access without reservations" queue, which is on the left side of Notre Dame (if you're facing it), and is marked by blue signage/banners. However, priority entrance is given to those who are attending Mass/services.

No reservations are needed to attend Mass or other liturgical services. There is a separate "Mass access only" queue, which is in front of the central portal, and is marked by a small white sign. Once you enter Notre Dame, you'll go directly to the Nave (the centre) to take a seat for Mass/the service.

Entrance starts 30 minutes ahead of the start time of whichever Mass/service you're attending. Entrance is still subject to the available capacity inside the cathedral. A maximum of 1,500 people can be seated for Mass/ services.

If you attend Morning or Afternoon Mass, you can stay and visit the rest of the main floor of the cathedral after Mass without having to exit/re-enter. FYI, Morning and Afternoon Mass during the week and on Saturday doesn't include the Notre Dame de Paris Choir. Evening Mass runs right until closing, so there isn't time to visit the rest of the main floor of the cathedral after Evening Mass (except on Thursday when Notre Dame is open late).

Thank you so much for all the details and advice. Much appreciated.