To help you optimize your website for Google’s Core Web Vitals, we have identified several potential problem areas and how to update them to improve your Core Web Vital scores. For more information about what each of the Core Web Vitals measures, how to measure, and ideal scores, see Google on Core Web Vitals.
Custom and Heavy Widgets
Both custom and heavy widgets can be slow because they load content from a third-party service, which requires calling an external API to retrieve and then load the content.
Note
Not all custom widgets are slow to load. It depends on how the custom widget was built.
Heavy widgets: Map, Twitter Feed, Facebook Like, Facebook Feed/Page, Facebook Comments, Audio (Soundcloud, Mixtape), Video (Custom, Youtube, Vimeo), Photo Gallery, Image Slider, Lottie Animations, Multi-location, Google Calendar, and Disqus.
How to Fix
To improve your Core Web Vitals scores:
eCommerce
Store is loaded dynamically with JavaScript. This can affect CLS because the Store takes longer to load than the rest of the content on the page. Because of this, we recommend moving the Store lower on the page instead of at the top.
How to Fix
To improve your Core Web Vitals scores:
Fonts
Web fonts can slow down your website because the browser has to download and load the full font family for each font and weight combination. Fonts are automatically downloaded and embedded within the HTML, up to 50KB. This speeds up how fast your browser renders custom fonts and helps prevent CLS. However, this is not always enough and is why we recommend using at most, two different font families and only a few weights from each.
How to Fix
To improve your Web Vitals scores:
Google Tag Manager
Google Tag Manager may download extra libraries and code that you don’t need, which can decrease LCP.
How to Fix
To improve your Web Vitals scores:
Images and Background Videos
Images and background videos are typically the largest asset that browsers download on your site. When there are too many images, one large image above the fold, or a video, it can cause a delay in LCP and increase in CLS because the browser has to download the elements before they can render. This typically happens with large background images/videos, image slideshows, background images with another image on top, or with multiple large images in a row at the top of the page.
Note
By “large image” we mean an image that takes up a majority of the page width.
How to Fix
To improve your Web Vitals scores: