How does lazy loading affect emails (hint: it doesn’t work)?

You've seen lazy loading work beautifully on websites where images load only as you scroll down the page. Can you do the same thing in email? The short answer is no. Lazy loading doesn't work in email, and here's why.

Email clients strip out all JavaScript, which means any lazy loading script you write will disappear before it ever reaches your subscriber's inbox. Even newer HTML attributes like loading="lazy" get ignored by email clients. That means all your images load (or fail to load) the moment the email opens, regardless of whether they're above the fold or buried at the bottom.

But Here's what matters: you're not designing for a web browser scroll experience. Email rendering is completely static. The client opens the message, loads what it's going to load, and stops. There's no scrolling event that triggers new content. This is why image optimization for email focuses on file size and format instead. You want files small enough to load instantly, not clever techniques. Want to see how your images actually perform? Run them through the email preview tests to check rendering across different clients so you know exactly what your subscribers see.