What Trys describes here mirrors my experience too—it really is worth occasionally taking a little time to catch the low-hanging fruit of your site’s web performance (and accessibility):
I’ve shaved nearly half a megabyte off the page size and improved the accessibility along the way. Not bad for an evening of tinkering.
Remember when I wrote about sizes="auto"? Well, it’s coming to Chrome! Hallelujah!
A no-nonsense checklist of good performance advice from Karolina.
Addy takes a deep dive into making sure your images are performant. There’s a lot to cover here—that’s why I ended up splitting it in two for the responsive design course: one module on responsive images and one on the picture element.
Progressive Enhancement allows us to use the latest and greatest features HTML, CSS and JavaScript offer us, by providing a basic, but robust foundation for all.
Some great practical examples of progressive enhancement on one website:
type="module" to enhance a form with JavaScript,picture element to provide webp images in HTML.All of those enhancements work great in modern browsers, but the underlying functionality is still available to a browser like Opera Mini on a feature phone.
Remy has an excellent improvement on that article I linked to yesterday on using srcdoc with iframes. Rather than using srcdoc instead of src, you can use srcdoc as well as src. That way you can support older browsers too!
This is a clever use of the srcdoc attribute on iframes.
The title is somewhat misleading—currently it’s about native lazy-loading for Chrome, which is not (yet) the web.
I’ve just been adding loading="lazy" to most of the iframes and many of the images on adactio.com, and it’s working a treat …in Chrome.
Using IntersectionObserver to lazy load images—very handy for webmention avatars.
The loading attribute for images and iframes is coming to Chrome. The best part:
You can also use
loadingas a progressive enhancement. Browsers that support the attribute can get the new lazy-loading behavior withloading=lazyand those that don’t will still have images load.
Jeremy Wagner offers a deep dive into lazy loading images (and video) with some advice for considering the no-JavaScript situation too.
Monica takes a look at the options out there for loading web fonts and settles on a smart asynchronous lazy-loading approach.