When should a toast arise in web app? [closed]

A toast should arise directly after: a user action has been completed. the system is now under a new state (e.g. error, warning or success)

1. How long should toasts stay up for?
2. When should you not use toast notifications?
3. Where should toast messages appear?
4. What is a toast on a website?

How long should toasts stay up for?

Issue #1: How long should toasts stay up for? A good length of time to keep messages up is 5 seconds plus 1 extra second for every 120 words, rounding up. This is how fast the average American reads. That means the shortest default that should be used as a best practice is 6 seconds.

When should you not use toast notifications?

Status indicator. Avoid using toasts for very critical information or alerts. Users may accidentally dismiss or entirely miss a toast, so it is best to avoid using toasts for important information. Additionally, avoid using toasts, critical or not, if it requires a user action.

Where should toast messages appear?

Toast messages ensure that the use of the application is not interrupted while providing necessary information for the user. They have no notification sounds associated with them and don't appear in the notification centers on any platform, but appear at the bottom of the viewport by default.

What is a toast on a website?

Toasts display brief, temporary notifications. They're meant to be noticed without disrupting a user's experience or requiring an action to be taken.