Are reservations necessary to walk the Highline in NY?

Not on weekdays.

Yes

Only on weekends. Easy to do because there are QR codes at entry/exit points

Reservations are required on the weekends. You scan a code with your smartphone and put in your personal info for contact tracing if needed. Can only enter at particular points.

Vanessa Hock is right, you don't need an appointment, because that was my experience. Various entry points and no one is checking for reservations. Just make sure you find out the hours of operation before heading out. Enjoy👍

Yes a reservation is required, but it takes about 2 minutes to do it,right on sight.

I was just there this past Sunday. A reservation was technically necessary, but it was in about 3 minutes from the time it was made, so it comes up pretty quickly.

The High Line is free. Given that the Covid-19 is still out there, they limit the number of people enter. But no reservation is needed.