The Championship high-flyers have met Posh's valuation for the forward, who has attracted plenty of interest from other clubs this month.
Boyd will now discuss terms with Palace before a transfer can be finalised.
"We have agreed terms with Crystal Palace for the transfer of George Boyd. The player will now talk terms with Palace," he said on the social networking site.
"It's obviously sad news for us at posh but we couldn't turn this opportunity down for the player.
"Many clubs have made bids which in truth were verging on taking the mick, however CP have backed their manager & met our terms today.
"George has been a palace fan all his life & now has chance if he joins them to help them get promoted to premier league."