Problem Description
- Your site has been optimized for speed
- If using WordPress, it could be using a plugin like WP Rocket
- When loading the page, styles are missing for a fraction of a second before they're loaded
- It appears like your website is flickering or jumping on page load
Your site is currently configured to provide the fastest loading time possible, and a component of this is serving the page content even before the styles are loaded. When the styles load, they then apply. This is called the first contentful paint.
Problem Resolution
If you explicitly choose not to have this occur because you don't like the visual appearance of it, the first contentful paint will occur much later than it could because you'll be choosing to delay it. This will dock you points in speed metrics, including Google PageSpeed, which might have a subtle effect on your SEO rankings.
If you're using a system like WP Rocket for WordPress to manage your site's speed automatically, look for the option to disable Optimized CSS Delivery and Delayed Javascript.
If your site is entirely custom coded, talk to your developer about moving scripts and styles out of the footer and in to the <head> tag, as well as removing async from javascript.
