1. What are Core Web Vitals?

Google uses Core Web Vitals to measure the user experience on a webpage. These metrics evaluate loading speed, visual stability, and interactivity.

2. Why does website speed matter for artificial intelligence?

AI platforms operate on strict compute budgets. They do not wait for slow pages to load. They skip slow websites entirely to save processing power, which means you will ultimately be invisible to your target audience as AI will not show your website to them.

3. How do third-party scripts affect performance?

Tracking pixels and chat widgets add extra data size to a page. They consume processing power. This directly increases loading times.

4. Why is website speed important?

Websie speed or the lack of it affect both your human and AI visitors, both of which have little to no patience for slow websites. Human visitors will abandon a website that takes too long to load, while AI will choose to ignore it.

Fixing Website Speed to Secure AI Search Visibility

Website speed is no longer a necessity only for human users, but is now crucial if you want to stay visible to AI. We explain the importance of understanding and tracking Core Web Vitals.

Written by:Marc FirthPublished: 25/05/2026

While it is hard to single out one factor as the most important aspect of a website, website speed is certainly near the very top.

In fact, even a one-second delay can have measurable business consequences. Research shows that every additional second of load time can reduce conversions by around 7% [1], while companies like the BBC reported losing 10% of users for every extra second their pages took to load [2].

Websites loading in under 2 to 3 seconds also see dramatically lower bounce rates. According to Google-backed research, 53% of mobile users abandon a page that takes longer than 3 seconds to load, while bounce probability increases by 32% when load time rises from 1 to 3 seconds, and by 90% at 5 seconds [3].

In 2026, ensuring a fast website no longer matters only for human visitors. Your website is increasingly accessed by AI systems, search crawlers, and LLM-powered research tools that surface recommendations and answers to users. While speed alone does not determine visibility, slow-loading websites can be crawled less efficiently and create more friction for indexing and retrieval [4]. If your website regularly takes 5+ seconds to load, you are likely losing both human attention and opportunities to appear in AI-assisted discovery [5].

Core Web Vitals

Google introduced Core Web Vitals as a way of measuring how users experience a website. It includes three metrics all of which are completely centred around the user experience: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS).

Image 1: Core Web Vitals, Source: Nitrogen Platform

Better quality and faster web experiences significantly impact conversion rates.

Largest Contentful Paint and Time to First Byte

Largest Contentful Paint measures how quickly the main content of a web page loads and becomes visible to the user. This metric evaluates the rendering speed of the primary text block or the largest image on the screen. A fast LCP reassures the user that the website is functioning correctly.
Google established a strict target threshold of 2.5 seconds or less for this metric. Everything above this threshold is considered to need improvement.

A supporting metric to LCP is Time to First Byte, i.e. the exact time between a user requesting a webpage and a client receiving the first byte of data from the server. A fast Time to First Byte establishes the foundation for all subsequent loading metrics.

A simple way to think about it:

TTFB = server response speed (“How quickly does the site start responding?”)
LCP = user-perceived loading speed (“When does the main content actually appear?”)

While this may sound technical, it is rather simple to understand and keep track of. More importantly, it is vital to understand its importance since it has a major impact on e-commerce revenue. Below is a list of real-life examples and how improvements in LCP affected their overall business.

Company	Metric Improvement	Business Impact
Vodafone	31% LCP improvement	8% increase in sales and 15% better lead rate
NDTV	55% LCP reduction	50% decrease in bounce rate
Agrofy Market	70% LCP improvement	76% reduction in load abandonment
AliExpress	2x LCP improvement	15% reduction in bounce rate

The larger the company, the larger the impact of LCP. For example, if an e-commerce site that produces 10 million in sales yearly has a two-second improvement in load time, their conversion rate can increase by 4%, i.e. they will experience a 400,000 pound increase in annual revenue.

Sites meeting all three Core Web Vitals thresholds experience 24% fewer page abandonment incidents.

Cumulative Layout Shift

Cumulative Layout Shift (CLS) measures the frequency and the severity of unexpected layout shifts and changes on a page. In other words, it measures website stability during the loading process.

Visual instability can drastically disrupt the user experience, and it is highly likely that we have all experienced such instabilities as users. They occur when late-loading images, unoptimised web fonts, or third-party advertisements unexpectedly affect the content that has already loaded by pushing it down the screen. A user may start clicking on a link or a button only to have it moved by content loaded too late, resulting in an unwanted action.

Maintaining a Cumulative Layout Shift score of 0.1 or less ensures a good user experience.

These are yet again not abstract claims and instructions. Multiple companies documented major engagement increases after fixing layout shifts. Yahoo Japan resolved their CLS issues, which led to a 98% reduction in poor pages and a 15% increase in page views per session. Ameba Manga improved its CLS score by a factor of 10. Users read two to three times more comics per session as a direct result. GEDI recorded a 77% reduction in CLS, which for them resulted in an 8% reduction in bounce rate.

Interaction to Next Paint

Interaction to Next Paint measures a page's overall responsiveness to user inputs throughout the entire lifespan of the user's visit. This metric captures data from mouse clicks, screen taps, and keyboard presses and records the absolute longest interaction delay during an entire page visit.

Users expect immediate visual feedback upon interacting with a page, which is why Google set strict thresholds for websites:

A score of 200 milliseconds or less yields a "Good" classification.
Scores between 200 milliseconds and 500 milliseconds fall into the "Needs Improvement" category.
Any measurement exceeding 500 milliseconds receives a "Poor" classification

How Core Web Vitals Impact E-commerce

Fixing Core Web Vitals directly impacts business revenue, and the fixes should be applied both to mobile and desktop. In fact, while mobile users generate between 70 and 75% of all website traffic, their conversions rates are still lower than those of desktop users. More precisely, while desktop users convert at an average rate of 3.2%, mobile users convert at an average rate of 2.8 percent. This makes mobile all the more important.

Website Speed and AI Discovery

As we’ve already mentioned, slow websites are ignored by both human visitors and generative engines.

When we talk about users, website speed is of the utmost importance as users no longer have the patience to wait for your website to load. As a matter of fact, according to research, every additional second of load time can reduce conversions by around 7%, lead to 11% fewer page views, and decrease customer satisfaction by as much as 16% [5].

The business impact becomes even clearer in real-world examples: Amazon found that just a 100-millisecond delay could cost 1% in sales, while Walmart reported a 2% increase in conversions for every one-second improvement in page speed [6].

When we talk about AI traffic and discovery, website speed is a strict requirement.

Generative engines evaluate hundreds of data sources in milliseconds, which means that AI crawlers like OpenAI's GPTBot or Anthropic’s ClaudeBot do not wait for bloated JavaScript files to render. In fact, these agents save compute costs by skipping rendering entirely and disconnecting immediately upon encountering a slow Time to First Byte.

AI companies pay high computational costs to process web data, which costs them real money. Since rendering JavaScript is the most expensive part of the crawling process, the majority of AI tools do not render JavaScript at all. They make a single request and immediately read whatever the server returns.

A slow server response causes the AI crawler to abandon the request immediately. Being expensive to crawl due to slow responses forces the AI platforms to allocate fewer resources to your domain or skip your pages completely. If AI doesn’t crawl your pages, it means less content is ingested, which ultimately results in your brand disappearing from AI search results.

For an e-commerce website, if you are not recommended by AI, you are invisible to your target audience. Speed determines whether the AI agents even try to read your content.

The slower your site, the more invisible you become.

How Speed Affects Citation Rates

A massive study of 700,000 pages conducted by Profound analysed the relationship between page reliability and AI citations. Pages exhibiting timeout failure rates above 75% received 18 times fewer citation interactions than stable pages.

Slow pages frequently received zero citations across the entire dataset.

A fast Time to First Byte guarantees a high AI citation rate. Time to First Byte matters more to AI agents than full page completion. Serving the first byte of meaningful content rapidly signals to the AI client about the server being active. This signal prevents the agent from prematurely terminating the connection.

What to Do Next

As part of a brand's marketing team, your number one priority is to ultimately have users convert. An easily measurable sign of growing revenue or ROI. There is a long road ahead to get your target audience to convert, but a safe way to achieve that is to have them remain on your website once they visit.

This refers to both your human visitors and your AI traffic. You need to ensure that they find your website, and that they stay on your website.

As we've mentioned before, website speed is one of your most important tasks, as it affects both human and Artificial Intelligence visits. If your website lacks speed, human visitors will abandon it, and AI will avoid it.

It is not necessary for you, as a marketer, to understand exactly how these technical features are achieved behind the scenes, but it is crucial that you understand how vital they are. You need to be able to effectively communicate this urgency to your development team, whether that’s your in-house crew or an external agency partner.

You also must track these metrics because they will clearly highlight where the issues lie. They will tell you if your human visitors are bouncing, or if your brand is practically invisible to the rapidly growing number of AI tools your target audience uses daily. This is why we have introduced you to Core Web Vitals, which simply and explicitly map out what your website is doing well and where it is lacking in terms of speed.

In the past, website speed conversations focused solely on human users. Today, you should be getting a significant portion of traffic from AI referrals. To capture that traffic, you must understand how AI approaches your site and how speed directly dictates your AI visibility. Consider the data:

Human impact: According to Google, as a page's load time goes from 1 second to 3 seconds, the probability of a user bouncing increases by a staggering 32%.
AI and Bot impact: AI crawlers and search bots operate on a strict 'crawl budget'. If your site is slow, bots will time out and leave before they can index your content, meaning you won't show up in AI-generated summaries or search results.

You can start fixing this process today by analysing your current Core Web Vitals metrics yourself, or we can step in to help. We can analyse your site's performance and recommend the exact next steps for speed improvement, maximising your AI visibility, and ultimately driving your ROI growth.

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