Core Web Vitals for startups: what to fix first | Lillian Purge

Core Web Vitals for startups: what to fix first

Core Web Vitals are one of those topics that sound deeply technical but in my experience they usually come down to a handful of very practical decisions. For startups in particular they can feel overwhelming because there is pressure to move fast ship features and acquire users, all while Google is telling you to improve performance metrics you may not fully understand yet.

I run a digital marketing firm and I work closely with early stage businesses including startups that are still finding product market fit. I have also dealt with the consequences when performance is ignored for too long. From experience Core Web Vitals do matter for startups but not all issues matter equally and not all fixes are worth doing at the same time. This article explains what Core Web Vitals actually mean in practice and what startups should fix first to get the biggest return on effort.

Why Core Web Vitals matter differently for startups

For large established brands Core Web Vitals are often about optimisation at scale. For startups they are more about removing friction and not creating unnecessary barriers to growth.

From experience startups are usually not losing rankings because they failed a performance score by a small margin. They lose traction because pages feel slow unstable or frustrating. Users bounce early and trust never forms. Core Web Vitals sit at the intersection of SEO and user experience. They influence how Google perceives quality and how users feel using the product. For startups that combination matters because you are still earning trust from both sides.

In my opinion Core Web Vitals are less about chasing green scores and more about avoiding obvious performance problems.

Understanding the three Core Web Vitals simply

Core Web Vitals measure three things. How fast the main content loads. How quickly the page responds to interaction. How stable the page feels as it loads.

From experience startups get stuck in the definitions and miss the intent. These metrics exist to catch poor user experience not to reward perfection. Largest Contentful Paint is about speed. First Input Delay which has now largely been replaced by Interaction to Next Paint is about responsiveness. Cumulative Layout Shift is about visual stability.

In my opinion understanding what frustrates users matters more than memorising metric names.

Fix visual stability before anything else

If I had to pick one Core Web Vitals issue for startups to fix first it would almost always be layout shift.

From experience pages that jump around while loading destroy trust instantly. Users try to click something and it moves. Text shifts. Buttons slide out of the way. This feels broken even if the site eventually loads quickly. Layout shift is usually caused by images without defined sizes dynamic banners loading late or fonts swapping after render.

The good news is this is often one of the easiest fixes. Setting image dimensions reserving space for dynamic elements and handling fonts properly removes most issues.

In my opinion a stable page that loads slightly slower converts better than a fast page that jumps around.

Make the first meaningful load feel fast

Startups often focus on overall load time while ignoring perceived speed.

From experience users care less about when everything finishes loading and more about when something useful appears. This is what Largest Contentful Paint is trying to measure. If your hero content product headline or key image takes too long to appear users hesitate. They may not consciously measure time but they feel delay.

Fixing this usually involves optimising hero images reducing render blocking scripts and prioritising critical content.

In my opinion making the page feel fast beats making the page technically perfect.

Avoid heavy JavaScript early on

One of the most common Core Web Vitals problems I see in startups is excessive JavaScript.

From experience this comes from using multiple tools trackers chat widgets and feature rich frameworks before they are truly needed. Heavy JavaScript delays interaction. Pages load but feel unresponsive. Buttons do not react immediately. This hurts Interaction to Next Paint.

Startups often add tools to compensate for uncertainty. Each one adds weight.

In my opinion the best early stage performance optimisation is restraint. Add only what you truly need.

Prioritise mobile experience first

Most startups underestimate how important mobile performance is even in B2B.

From experience Core Web Vitals failures often appear far worse on mobile devices because of slower connections and weaker hardware. A site that feels acceptable on a laptop can feel painful on a phone. Fixes should always be validated on mobile first. Image sizes touch targets and script execution matter more here.

In my opinion mobile performance is where startups win or lose early trust.

Image handling is low hanging fruit

Images are one of the biggest contributors to poor Core Web Vitals and one of the easiest to improve.

From experience startups often upload large uncompressed images or rely on default platform behaviour. Optimising images using modern formats sizing them correctly and lazy loading non critical visuals improves performance quickly. This alone can improve Largest Contentful Paint and overall responsiveness.

In my opinion image optimisation is one of the highest return tasks a startup can do.

Hosting and infrastructure decisions matter early

Startups sometimes choose cheap hosting to save money early on. From experience this often creates performance ceilings that are hard to escape later.

Slow servers increase time to first byte which affects every Core Web Vitals metric indirectly. You do not need enterprise infrastructure but you do need reliable fast hosting.

In my opinion hosting is not the place to cut corners if growth is the goal.

Fonts and third party scripts cause hidden problems

Fonts and third party scripts are common sources of layout shift and delayed interaction.

From experience web fonts loading late cause text to reflow. Third party scripts block rendering or interaction. Startups often add analytics chat tools heatmaps and A B testing platforms without measuring impact. Each tool feels small. Together they hurt performance significantly.

In my opinion every third party script should justify its existence.

Do not chase perfect scores too early

One of the biggest mistakes startups make is chasing perfect Core Web Vitals scores too early.

From experience this leads to over engineering and delayed launches. Core Web Vitals are thresholds not competitions. Being good enough matters far more than being perfect. If users can interact quickly content loads smoothly and the page feels stable you are likely in a healthy place.

In my opinion performance should support momentum not slow it down.

Use real user data not just lab tests

Startups often rely only on lab tools like Lighthouse.

From experience lab data is useful but it does not reflect how real users experience the site. Core Web Vitals are based on real user data. Tools that show field data reveal far more meaningful issues. If real users are struggling that matters more than test scores.

In my opinion always prioritise real world experience over synthetic metrics.

Sequence fixes rather than doing everything at once

Trying to fix all Core Web Vitals at once often leads to confusion and wasted effort.

From experience the best approach is sequencing. Fix layout shift first. Then improve perceived load speed. Then reduce interaction delay. Each improvement builds on the last.

In my opinion sequencing reduces risk and preserves development focus.

Core Web Vitals and SEO expectations for startups

It is important to be realistic about how Core Web Vitals affect SEO for startups.

From experience performance alone will not make a new startup rank. Content relevance authority and intent still matter more. However poor Core Web Vitals can hold back growth and reduce conversion even if rankings are fine.

In my opinion Core Web Vitals are enablers not growth engines.

When to invest more deeply in performance

As startups grow and competition increases performance becomes more important.

From experience once you are competing head to head with similar products performance differences can influence rankings and user choice. At that stage deeper optimisation makes sense. Early on focus on removing obvious friction rather than squeezing every millisecond.

Final thoughts from experience

For startups Core Web Vitals should be treated as a usability checklist not a technical obsession.

From experience fixing visual stability perceived speed and responsiveness delivers the biggest early gains with the least effort. Performance should make your product feel trustworthy and easy to use. If it does that Google metrics usually follow.

If you fix what users feel first you rarely go far wrong.