Last Minute Louvre?

I'll be in Paris mid-May and had the same thought. But I'm a compulsive planner so here's what I just did. I went to the Louvre website, www.louvre.fr, and searched for tickets for next week. As of today (Sunday) there is one slot open at 4:30pm on Tuesday. Afternoons open up later in the week. To get morning entry you have to reserve further ahead, maybe 5-7 days. Time of your visit may affect this as I think the tourist hordes (including me) will be descending on Paris later this spring and summer. If you don't mind skipping a visit then I would say just wing it. But if your heart is set on going, then I say plan ahead. Its so easy with the internet. Enjoy your trip!

Yes, I, too have been monitoring the ticketing pages on the Louvre website. It looks like you will be there the end of April? Right now that last week of April still looks wide open. It looks like the all the morning slots are gone through the 20th so that's 10 days out. The 21's has all the 10A slots gone but the rest of the day is open so far. Tomorrow all slots are gone except the 10A slot but the rest of the week has lots of afternoon times open.

I'd keep an eye on the ticketing page and book if it looks like the afternoon times on the day that will work for you are starting to fill.

https://www.ticketlouvre.fr/louvre/b2c/index.cfm/calendar/eventCode/MusWeb

I waited too late to get a morning slot for the first day I wanted to go so booked afternoon for that day. I'll go back at least once more a week later and went ahead and booked a 9A entry time that day.

I think this will be a year of watching ticketing sites and being ready to pounce if things look like they are booking up. No hard and fast rules this spring!