Paris in February - Pre-Booking necessary at Eiffel Tower and Lourve?

My answer is in connection with the Louvre. Even during high season, I have not seen long lines for purchasing tickets at the Louvre and I go there just about every trip that I take to Paris. That being said, I don't see any downside other than the fact that you will be "stuck" with going to the Louvre on the date that you chose. Also, please note the advance ticket sold at the Louvre's website is not a true "skip the line" ticket. You still have to go through and cannot skip the security line and that line can be long. Also, the ticket guarantees you admission within 30 minutes of the stated time and not that you can just show up, show the ticket and walk in.

There will still be lines, just not impossible ones. We walked up to Eiffel Tower late on a February afternoon and went right up. However, there were ticket lines with people waiting and then open ones that I think looked too good to be true to people. I got my Louvre ticket at the tabac shop and went right in, but there were folks in line for tickets. Your line-skipping, crowd avoidance strategies will be useful. You still need to be a little savvy. If you can book ahead then why not do it. It’s still a time-saver. The two biggest sights in Paris are worth planning around.

Thank you for your advice!

And remember the pyramid entrance is not your only entrance to the Louvre. You can either enter below from the Metro Stop or by walking down the stairs on either side of the Arc de Triomphe du Carrousel, the Arc across the road from the pyramid heading towards Jardin des Tuileries. There is a shopping mall underground and an entrance into the Louvre. The inverted pyramid is at this location.

A recent video showing the alternate entrance and locker locations if needed:https://www.youtube.com/watch?v=xIVojnJ6DG4

Enjoy your trip, 7 more months until I return.

Thank you brushtim!

I use the paris museum pass, while not economically sound to one museum. You can visit in doses, and skip the ticket lines.
I find that more than 1 1/2 hours at a museum, everything just starts to seem like "oh another nice piece of art" . The Louvre is so large! you might consider going for a while and come back later. Plan on the things you want to see. At the information desk there, they are very helpful in mapping out the things you want to see and offer some suggestions of other things you may not have considered there. Then go out and take a walk, get a bite to eat and go back or try another. Orsay museum is a real treat, which I favor over Louvre, just across the river, or go to l'orangerie and see Monet's water lily's. (usually not big crowds there).

Other favorites using the museum pass are St Chapelle, Military museum (see Napoleans tomb! and the armor exhibit!), Rodin museum nearby. The Cluny museum also!
As far as Eiffel tower, I've never been up it. Fun to go under it and take a selfie looking up the middle. I like to go up Arc de Triumph, Less lines, fabulous view, and the view has the Eiffel tower in it!
You will love it! Enjoy.

the risk of booking the Eiffel Tower ahead of course is that the weather especially in winter can be dreadful. We booked Oct 5 a couple of years ago and it was literally the only rainy day that entire month. It was actually a wonderful day to visit the Tower:
https://janettravels.wordpress.com/2016/05/16/the-eiffel-tower-in-the-rain/
but it would not have been if it had been fogged in. In February, I'd probably plan to get tickets the day of and probably walk up the first two floors (those lines are usually short and you can get a ticket to the top when you buy the walk up ticket)

For the Louvre. I have been a couple of dozen times and never had a long security line at the Carrousel entrance nor spent that much time in the ticket line. In February I'd just get tickets on arrival from a machine.

For the Louvre, I'd suggest going on a Friday. We had no lines when we went from April, and we entered from the pyramid. Monday (as predicted by the RS book) was packed since many other museums are closed.

We got lucky with the Eiffel Tower. We went when the weather was cold and rainy, and we didn't encounter any lines for tickets.