Webster’s Edinburgh career began under former Scotland coach Frank Hadden in 2002 and, in 10 seasons, he made 127 appearances, scoring 34 tries. In 37 Scotland appearances between 2003 and 2009 he scored eight tries.
Following two seasons of enforced absence due to an Achilles problem, Webster returned to full fitness in September but has been unable to dislodge the prolific Dutchman Tim Visser and Scotland international Lee Jones.
Webster said: “I’d like to thank everyone at Edinburgh Rugby for their support over the past ten years. I’ve had a fantastic time playing for the club and representing Scotland on the world stage – experiences I will never forget.
“It’s been a tough year for me having finally got myself fit but unable to secure first team action and I felt that the timing was right for me to leave the club and seek out new playing opportunities.
“Rugby has been a huge part of my life for more than 25 years and I still love the game as much as I did when I first picked up a ball.
“This extra time allows me to take stock of the great experiences I’ve had and look ahead to the next chapter in my life.”
Edinburgh managing director, Craig Docherty, said: “Ten seasons at the peak of any professional sport is a significant achievement and few more so than the intensely competitive modern rugby game.
“On behalf of the Edinburgh players, coaches, staff and supporters, I’d like to thank Simon for his time at the club and wish him all the best for the future.”
Webster’ notable international highlights include starting all five of Scotland’s Rugby World Cup matches in 2007 (the only player to do so), twice lifting the Calcutta Cup (2006 and 2008), helping Scotland defeat Argentina in Buenos Aires in 2008, and playing all three matches in Scotland A’s IRB Nations Cup success in Bucharest in 2009.