What this does is hide the preload element through CSS. Now we have our images loading through HTML so they are cached in our browser, but the container element is not visible. Feel free to reach out if you have any questions and make sure to sign up on our mailing list: AmplitudeJS to stay up-to-date with all of the upcoming features for AmplitudeJS!
If you like what you read, consider getting our book or you can buy us a beer. Builder, creator, and maker. Dan Pastori is a Laravel certified developer with over 10 years experience in full stack development. When you aren't finding Dan exploring new techniques in programming, catch him at the beach or hiking in the National Parks.
Exit Fullscreen. Support future content. Written By Dan Dan Pastori. Follow danpastori. We ran tests on a site that uses JavaScript to lazy-load responsive images. Preloading resulted in images loading 1. Responsive images are supported in all modern browsers while preloading them is supported only in Chromium-based browsers. This kicks off a request using the same resource selection logic that srcset and sizes will apply. Let's say you're dynamically-loading hero images as part of a slideshow and know which image will be displayed first.
In that case, you probably want to avoid waiting for the script before loading the image in question, as that would delay when users can see it. Open this example website in a new tab. Using preload helps here because the image starts loading ahead of time and is likely to already be there when the browser needs to display it. To see the difference that preloading makes, you can inspect the same dynamically-loaded image gallery but with preloaded first image by following the steps from the first example.
An alternative way to avoid the problem would be to use a markup-based carousel and have the browser's preloader pick up the required resources. However, this approach may not always be practical. For example, if you are reusing an existing component, which is not markup-based. If you have different background images for different screen densities, you can specify them in your CSS with the image-set syntax. The browser can then choose which one to display based on the screen's DPR.
The above syntax ignores the fact that vendor prefixes are needed for this feature in both Chromium and WebKit based browsers. If you're planning to use this feature, you should consider using Autoprefixer to address that automatically. You can inspect this issue on an example website with responsive background image. If you know of any good preloading tricks, including any improvements to the techniques shared here, kick start my heart with your wise words of preloading wisdom ;.
Great article Jeff, I will be using this for my new projects. Can you write an article about caching images? This is a very good post and i also like your blog page layout too. Bookmarked your site and will stop by again. Montana Flynn: Actually yes, I have something in mind for a caching article and will be working on it this coming month. Stay tuned.. Miller Medeiros: Absolutely — that is another fine way to preload images.
At the beginning of this article, I link to my initial post using the CSS-only method , and also the follow-up article, wherein I attempt to improve the original technique. The code is not eaten :. You just have to place your pointer over the code and it will expand… Great article, thanks for sharing. Hi justin, image sprites are a great way to improve performance by reducing the number of HTTP requests.
I use them here at Perishable Press and on many other sites — they are an important tool and a good way to preload your CSS background images. The preloading method described in this article is actually geared more toward caching of bulk images such as used in galleries, portfolios, shopping carts, etc. Incase you cant read this again — your image sources on the second method are repeated rather than incrementing the image number… copy and paste are a bitch. Main Menu. Perishable Press. USP Pro : Unlimited front-end forms for user-submitted posts and more.
About the Author. Security Specialist. WordPress Buff. Really Simple Browser Detection with jQuery. Great tips Jeff, thanks a lot. I tend to prefer JavaScript Method 1, mostly because of its easy implementation.
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