Will low-quality images improve my Core Web Vitals score?
There are often two ways to game an SEO metric: the easy way and the hard way. The easy way is to boost the metric by sacrificing anything that slows it down, content, functionality, or experiences. Or - optimize the hard way. Find ways to build small improvements without compromising content.
One example of finding an easy way to score well is to compress image files beyond all recognition. These tiny files can be classed as the largest contentful paint and load almost instantly. Fast loading content will also free up the main thread for a faster first input delay. The result is pages that score well in Core Web Vitals but have blurry headline images.
But, maybe this is a masterstroke. If the value of the higher scores translates into more organic traffic, it may outweigh the negative effects of sacrificing content quality. Utilitarianism meets SEO.
One publisher asked Google's Search Advocate John Mueller if this practice was a good idea or not.
The answer is both wonderfully vague, it 'sounds like a bad idea' and sparklingly clear. The unspoken message in this exchange is that, yes, compressing images to extreme lengths will probably help improve Core Web Vital scoring .
But, the larger point is that metrics should always be a guide toward a better user experience. Some judgment has also to be factored in. If it sounds like a bad idea, it almost certainly is.
As Mueller states, if users don't like the content, any victories are going to be short-lived. What reader wants blurry image quality from a publication? It may improve Core Web Vital results, even page ranking. But when users start to drip away, page views go down, session time starts to fall, the impact on SEO will be far greater. Not to mention the damage to the reputation of the publication as readers click, see fuzzy images, and decide to leave the page.
Users will always demand quality and speed. While there will always have to be compromise and tradeoffs between the two, the answer is rarely one or the other. Core Web Vitals are not designed to make publishers obsess over scoring, rather the opposite. They are the closest, simplest way to quantify the basics of a good mobile experience. This should help publishers cut their reliance on the word of metrics and start thinking about the user experience first.
If any strategy to improve scores sacrifices a noticeable part of the user experience, it may improve scores but do lasting damage to the overall SEO mission. Focusing on the users optimize without weakening the message. Make pages as fast as possible in ways that users can actually feel, and not give webmasters too many metrics to know where to focus.
There are many simple and achievable ways to optimize images for faster loading times You can find our complete guide to optimizing images for faster largest contentful paint here.