How to build a countdown timer using CSS

Countdown timers are a common feature on websites, often used to enhance user engagement for events and sales, and can be implemented using either JavaScript or CSS. This tutorial provides a step-by-step guide to creating a basic JavaScript countdown timer with start and pause functionalities, and then progresses to building a CSS-only countdown timer. Both methods are compared using Chrome DevTools to assess their performance, revealing that the CSS-only timer has a slight advantage in terms of fewer requests and faster initial load time, though it incurs higher rendering and painting times. The CSS-only approach offers simplicity with minimal scripting overhead, making it suitable for lightweight applications, while the JavaScript method allows for more complex interactions and efficient DOM rendering, albeit with increased scripting complexity and CPU usage. The choice between these approaches depends on the project's specific requirements and the trade-offs developers are willing to accept.