Morsel #11: how to check if a DOM element is in the viewport

In my line of work, I struggle with finding DOM elements that cause issues but are otherwise hidden—by display:none—or obscured by above-the-fold menus. I came across the latter the other day and the issue was lazy-loading. I wasn’t sure whether the element classed as “in the viewport” despite not being immediately seen by the user unless they unfolded the menu.

So I looked for a way to check and came across a JavaScript method called getBoundingClientRect(). It returns a DOMRect object that shows the size (width and height) and position (x and y coordinates) of an element in relation to the viewport.

There are other ways to do it but this seemed the easiest for me (and coolest because I’d never heard of it before). Here’s an example taken from Geeks for Geeks:

function myfunction(value) {
    const item = value.getBoundingClientRect();
    return ( >= 0 &&
        item.left >= 0 &&
        item.bottom <= (
            window.innerHeight ||
            document.documentElement.clientHeight) &&
        item.right <= (
            window.innerWidth ||

const elementToCheck = document.getElementById('div1');

window.addEventListener('scroll', () => {
    if (myfunction(elementToCheck)) {
        console.log('Element is visible in viewport');
    } else {
        console.log('Element is not visible in viewport');

After I put my element in as the value of elementToCheck, it came up as “in the viewport” and therefore shouldn’t be lazy-loaded. Easy fix!

Morsel #10: Ticking all the boxes Morsel #12: styling a WordPress post to look like a Bluesky post