Custom Alert/Confirm/Prompt Popup Box JavaScript Library – attention.js
attention.js is a vanilla JavaScript plugin used for creating custom alert, confirm or prompt dialog boxes on the page.
JavaScript & CSS prompt
Pretty Non-blocking Dialog Popup JavaScript Plugin – Prompt-Boxes
The Prompt-Boxes JavaScript plugin used to create nice, clean alert/confirm/prompt dialog boxes and toast-like notification popups on your web app.
Multi Purpose Dialog Library In JavaScript (ES 6) – Dialog.js
Dialog.js is a pure JavaScript plugin for creating modern, easy-to-style dialog boxes using HTML dialog element.
Simple Customizable Modal Dialog JavaScript Plugin – popupmodal.js
popupmodal.js is a vanilla JavaScript plugin helps you create responsive, customizable modal dialog popups with ease.
Pure JavaScript Toast & Dialog Popup Library – Alerty
Alerty is a tiny, easy, dependency-free JavaScript library that helps you create Material Design styled alert/confirm/prompt dialog popups and toast notifications in the screen.
Pretty Animated Popup JavaScript Library – x0popup
Just another JavaScript popup library which creates animated, good-looking and highly customizable popup windows to replace the native alert, confirm, prompt dialog boxes.