Paris restaurants, how far in advance to book reservation?

If you know for sure, book now. I have already booked my birthday dinner in April.

We used to be able to get into most of the places we liked with a 3 or 4 day advance reservation but one of those places was complete booked for all of October last year when we got to Paris and we ended up missing out. Years ago we could not get into a well known place two weeks in advance and last year close friends were not able to get reservations at our favorite place for celebration dinners for the entire month they were there.

Very well known places a month or two is prudent. Most places a week or so is enough. Little local spots, often the day before is plenty. Even they fill up. We went to a little spot in Batignolles we always go to when in the area last spring. I made a reservation noon that day and when we got there at 8 it was pretty empty but they asked if we had a reservation. I joked with my husband that it looked like we didn't need one. by 8:30 the place was complete full with people who had reserved.

And if you want to be more spontaneous -- still make a reservation that day or the day before. Sometimes that is possible. Post COVID just as museum advice is obsolete, it may be that restaurant advice is too.

There are just more people in Paris than every before. Prices reflect higher demand and reservations need to be made as soon as you can. It always depends upon the restaurant but some, where I once could call a day or two in advance, now require double the lead time. Very popular restaurants now take weeks.