Analytics
Core Web Vitals Overview
Core Web Vitals are a set of metrics introduced by Google that are vital to providing a high-quality user experience on the web. These metrics measure the speed, responsiveness, and visual stability of a website, offering an objective way to assess the user experience. They play a crucial role in understanding how users interact with websites and in identifying areas that need improvement.
Core Web Vitals include three primary metrics:
- Largest Contentful Paint (LCP): Measures the time it takes for the main content of a page to load.
- First Input Delay (FID): Assesses the time it takes for a website to become interactive.
- Cumulative Layout Shift (CLS): Quantifies the amount of unexpected layout shift during the loading phase.
Importance in Web Performance and User Experience
Tracking and optimizing these vitals are essential for several reasons:
- Enhancing User Satisfaction: A website that loads quickly and interacts smoothly is more likely to keep users engaged and satisfied.
- Improving SEO Rankings: Google uses Core Web Vitals as a ranking factor. Websites that perform well on these metrics are likely to rank higher in search engine results.
- Boosting Conversion Rates: Faster, more responsive websites have been shown to have higher conversion rates. Users are less likely to abandon a site that performs well.
- Reducing Bounce Rates: Websites with low performance scores often suffer from higher bounce rates, as users tend to leave sites that are slow or unstable.
In the next sections, we will delve deeper into each of the Core Web Vitals, explain how our analytics script tracks these metrics using Chrome's Core Web Vitals data, and provide insights into how you can use this information to optimize your website's performance.
Understanding The Data
Chrome's Core Web Vitals data provides a comprehensive set of metrics that capture real-world user experience on a webpage. This data is crucial for website owners and developers as it offers insights directly from the user's perspective. The metrics are user-centric and focus on aspects of web usability such as load time, interactivity, and the stability of content as it loads.
By leveraging this data, website owners can:
- Gain a clear understanding of their site's performance from the user's point of view.
- Identify specific areas for improvement based on real-world usage data.
- Benchmark performance against industry standards or competitors.
How It Enhances Web Analytics
Integrating Chrome's Core Web Vitals data into our analytics script enhances the standard web analytics approach by adding a layer of user experience metrics. This integration allows for:
- More Informed Decision-Making: With detailed UX metrics, you can make informed decisions to enhance your website's performance.
- User-Centric Optimization: Focus on what matters most to your users for a better overall web experience.
- Comprehensive Performance Analysis: Combine traditional analytics with UX metrics for a more holistic view of your website's performance.
Largest Contentful Paint (LCP)
LCP is a critical Core Web Vital that measures the time it takes for the largest content element on your webpage to become visible to the user. This could be a large image, video, or block of text. LCP is an important metric because it provides a user-centric view of load performance, reflecting the real-world experience of your site's visitors. A fast LCP helps assure the user that the page is useful and responsive.
- Good LCP (<2.5 seconds): Indicates a fast and responsive site.
- Needs Improvement (2.5 - 4 seconds): Suggests potential areas for optimization.
- Poor LCP (>4 seconds): Highlights urgent need for performance improvements.
Analyzing LCP data helps pinpoint specific elements that slow down your site, allowing you to target them for optimization.
A slow LCP can lead to a negative user experience, potentially increasing bounce rates and reducing conversions. Users often equate the speed of loading with the efficiency of the site, making LCP a key factor in user satisfaction.
First Input Delay (FID)
FID measures the time from when a user first interacts with your website (i.e., when they click a link, tap a button, or use a custom, JavaScript-powered control) to the time when the browser is actually able to begin processing event handlers in response to that interaction.
This metric is a key indicator of a website's interactivity and responsiveness. A low FID is crucial for ensuring that a website feels smooth and usable, particularly for web pages where user interaction is critical, such as login pages or e-commerce sites.
A good FID is less than 100 milliseconds.
- Good FID (less than 100 milliseconds): Indicates that the site is interactive and responsive.
- Needs Improvement (100 - 300 milliseconds): Suggests that users may experience some delay in interaction.
- Poor FID (greater than 300 milliseconds): Impacts user experience negatively, indicating significant interaction delays.
Optimizing for FID involves reducing JavaScript execution time, which can delay a page's interactivity. This includes minimizing the amount of JavaScript loaded on a page, deferring unused JavaScript, and optimizing page elements for quick interactions.
Cumulative Layout Shift (CLS)
CLS measures the visual stability of a website. It quantifies the frequency and magnitude of unexpected layout shifts on the page. A layout shift occurs whenever a visible element changes its position from one rendered frame to the next.
This metric is essential because it affects the user experience. High CLS can be frustrating for users, as it leads to elements moving around unexpectedly, which can result in accidental clicks or difficulty reading content.
A good CLS score is less than less than 0.1.
- Good CLS (less than 0.1): Indicates a stable and visually consistent site.
- Needs Improvement (0.1 - 0.25): Some users may experience minor layout shifts.
- Poor CLS (greater than 0.25): Suggests significant visual instability, negatively impacting user experience.
To improve CLS, consider the following strategies:
- Ensure Images and Videos Have Dimensions: Specify width and height attributes to prevent layout shifts while media loads.
- Reserve Space for Ad Elements: Pre-allocate space for ads or embeds to avoid sudden layout changes.
- Avoid Inserting New Content Above Existing Content: Especially for content that pushes down other content when the page is already in view.
What data is processed?
Below is an example request logged by Fullres Analytics for Core Web Vitals data. Utilize our tool's ability to segment Core Web Vitals data by different parameters such as device type, geographic location, or user behavior. This can help you identify specific areas or user groups where performance improvements are most needed.
{
"type": "vitals",
"vitals": {
"fcp": {
"name": "FCP",
"value": 292.40000000596046,
"rating": "good",
"delta": 292.40000000596046,
"entries": [
{
"name": "first-contentful-paint",
"entryType": "paint",
"startTime": 292.40000000596046,
"duration": 0
}
],
"id": "v3-1705071989401-1696324372710",
"navigationType": "reload"
},
"lcp": {
"name": "LCP",
"value": 292.40000000596046,
"rating": "good",
"delta": 292.40000000596046,
"entries": [
{
"name": "",
"entryType": "largest-contentful-paint",
"startTime": 292.40000000596046,
"duration": 0,
"size": 42290,
"renderTime": 292.40000000596046,
"loadTime": 0,
"firstAnimatedFrameTime": 0,
"id": "",
"url": ""
}
],
"id": "v3-1705071989401-5241309447172",
"navigationType": "reload"
},
"inp": {
"name": "INP",
"value": 24,
"rating": "good",
"delta": 24,
"entries": [
{
"name": "pointerdown",
"entryType": "first-input",
"startTime": 17262.30000001192,
"duration": 24,
"processingStart": 17266.600000023842,
"processingEnd": 17266.80000001192,
"cancelable": true
}
],
"id": "v3-1705071989401-2703612351589",
"navigationType": "reload"
},
"cls": {
"name": "CLS",
"value": 0.06519485071472844,
"rating": "good",
"delta": 0.06519485071472844,
"entries": [
{
"name": "",
"entryType": "layout-shift",
"startTime": 380.80000001192093,
"duration": 0,
"value": 0.0036713359571575372,
"hadRecentInput": false,
"lastInputTime": 0,
"sources": [
{
"previousRect": {
"x": 2334,
"y": 502,
"width": 453,
"height": 362,
"top": 502,
"right": 2787,
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},
"currentRect": {
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}
}
]
},
{
"name": "",
"entryType": "layout-shift",
"startTime": 444.2000000178814,
"duration": 0,
"value": 0.06152351475757091,
"hadRecentInput": false,
"lastInputTime": 0,
"sources": [
{
"previousRect": {
"x": 227,
"y": 630,
"width": 1876,
"height": 234,
"top": 630,
"right": 2103,
"bottom": 864,
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},
"currentRect": {
"x": 0,
"y": 0,
"width": 0,
"height": 0,
"top": 0,
"right": 0,
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}
}
]
}
],
"id": "v3-1705071989401-8969624851530",
"navigationType": "reload"
}
},
"width": 1522,
"height": 586,
"userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
"referrer": "",
"utmSource": null,
"utmMedium": null,
"utmCampaign": null,
"utmTerm": null,
"utmContent": null,
"site": "yourwebsitecom",
"url": "https://yourwebsite.com/about-us"
}