It's important to show the progress of a task to the user, specially for those long tasks that takes more than 5 seconds to be achieved. Nobody wants to get stucked in a webpage after execute an action and without any advice of what's going.
The following libraries will help you to display the progress of a task easily with a couple of files and lines of code. Some of them are automatic and will be triggered when an ajax call is executed, others needs to be handled manually with customized events.
You can design your own template for progress bars or simply customize them. You can use ProgressJs to show the progress of loading contents (images, videos, etc.) on the page to the users. It can be used on all elements including textboxes, textareas or even the whole body. It's light-weight, easy to use, customizable, free and open-source.
NProgress is a progress bar. Featuring realistic trickle animations to convince your users that something is happening. The setup can be a little tricky.
Pace.js is a wonderful and automatic page load progress bar. You just need to include pace.js and a CSS theme of your choice (more than 6 available), then you'll get a beautiful progress indicator for your page load and ajax navigation. This plugin is ready to use, however you can change some properties at the initialization if you want.
If you know another awesome loading plugin, please share it with us in the comment box !