Question

Im sending and receiving posts with ajax and php, now when would be the best time to update my response to my html, after send post or before?

Answer 1

It depends.

The most common approach I have used/seen is to update your HTML after you receive a response from the PHP script you are executing via AJAX.

jQuery example:

$.post('script.php', {name_1: value_1, name_2: value_2}, function(data){
  /*
    this is the function that is fired upon a successful AJAX execution
    the data variable contains the data script.php outputs
  */
  //update html here
});