Most seating tools are either a generic diagram app hat knows nothing about your guests, or an enterprise venue platform on a 12-month contract.
SeatPlanning is the standalone middle: drag tables onto a canvas import guests from Excel, seat everyone, then collet RSVPs, send invitations and check people in with QR codes. Guests can pick their own seat. Export a print-ready PDF or Excel.
2D by design, no 3D renders, no sales call. Free tier needs no account.