The 22-year-old announced the news on Twitter.
He said: “Another chapter closes! Thankyou to everyone involved @crawleytown for the past couple seasons! Met some great people and want to wish my teammates all the best in the future!”
Current and past teammates replied to wish him luck.
James Tilley said: “All the best brother.”
Davide Rodari said: “Gonna miss you Ty.”
Ashley Nadesan said: “Been a pleasure brother.”
Goalkeeper Alfie Jones said: “Just a lovely person you are.”
And Archie Davies, who also left the club, said: “What a player.”
Frost had never played a professional game of football before he arrived at the Broadfield Stadium in August 2020.
Frost learnt his trade at Reading. He joined the Championship club when was just nine and went through the ages until he was released in July 2020.
Defender Davies, 23, also left the Reds, he tweeted: “Just want to say thank you to everyone associated with @crawleytown for the last 2 years. Not always been easy but I can take experiences that will live with me forever. Wish everyone the best going forward.”
Southampton loanee Will Ferry has gone back to his parent club.
Keeper Alfie Jones also left the club, tweeting: “Was fun. All the best to the boys.”