HttpService:GetAsync() is not yielding

I’m requesting a large file from my servers using HttpService:GetAsync() but it is not waiting until all the data is received.

local req = HttpService:GetAsync(url)
local json = HttpService:JSONDecode(req)

Is there any way I can wait for it all to load? Any help would be appreciated.

repeat task.wait() until string.len(req) >= 0 --change to expected content length

This would go between the two lines.