Select Page

JavaScript print Events

David Walsh
Published: December 30, 2022

Media queries provide a great way to programmatically change behavior depending on viewing state. We can target styles to device, pixel ratio, screen size, and even print. That said, it’s also nice to have JavaScript events that also allow us to change behavior. Did you know you’re provided events both before and after printing?

I’ve always used @media print in stylesheets to control print display, but JavaScript provides beforeprint and afterprint events:

function toggleImages(hide = false) {
  document.querySelectorAll('img').forEach(img => { = hide ? 'none' : '';
// Hide images to save toner/ink during printing
window.addEventListener('beforeprint', () => toggleImages(true))
window.addEventListener('afterprint', () => toggleImages());

It may sound weird but considering print is very important, especially when your website is documentation-centric. In my early days of web, I had a client who only “viewed” their website from print-offs. Styling with @media print is usually the best options but these JavaScript events may help!

  • JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why “hold up the show” when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world…

  • CSS vs. JS Animation: Which is Faster?

    How is it possible that JavaScript-based animation has secretly always been as fast — or faster — than CSS transitions? And, how is it possible that Adobe and Google consistently release media-rich mobile sites that rival the performance of native apps? This article serves as a point-by-point…