I create a website where a user needs to to fill in a form. After that the form starts to call an API with this input. Unfortunately the API response is very slow and sometimes user has to wait about one minute. I have read from [UX Movement][1] that if the user needs to wait so long it is better to use a progress bar instead of a spinner. I cannot predict how long the api call will last. Therefore, an accurate display of the progress is difficult. Do you have any experience or ideas how to handle this? [1]: http://uxmovement.com/navigation/progress-bars-vs-spinners-when-to-use-which/