Spain · Madrid Completed: Apr 7, 2026 20:06 UTCMobile 375 × 812
Desktop 1440 × 900
Score: 78 / 100
Based on 8 categories, 0 sections
The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.
Weights reflect general web best practices. Individual needs may differ.
Content-Security-Policy header is missing
No Content-Security-Policy header found
5 button(s) with no accessible text
Cross-Origin-Embedder-Policy header is missing
Cross-Origin-Opener-Policy header is missing
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Industry-standard audits powered by Google Lighthouse.
Key metrics that affect user experience.
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
3.32 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
6.26 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.35 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
4.37 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
6.64 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.
HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
| URL | Transfer Size | Duration |
|---|---|---|
| www.swift.org/assets/javascripts/new-javascripts/vendor/anime.iife.min.js | 75.3 KiB | 2.0 s |
| www.swift.org/assets/javascripts/new-javascripts/application.js | 7.0 KiB | 1.1 s |
| www.swift.org/assets/javascripts/new-javascripts/color-scheme-toggle.js | 3.5 KiB | 962 ms |
| www.swift.org/assets/javascripts/new-javascripts/landing.js | 1.6 KiB | 962 ms |
| www.swift.org/assets/stylesheets/new-stylesheets/application.css | 16.5 KiB | 1.1 s |
| www.swift.org/assets/javascripts/new-javascripts/hero.js | 8.7 KiB | 1.3 s |
| developer.apple.com/assets/metrics/scripts/analytics.js | 83.2 KiB | 1.9 s |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| developer.apple.com/assets/metrics/scripts/analytics.js | 81.8 KiB | 26.5 KiB |
| www.swift.org/assets/javascripts/new-javascripts/hero.js | 8.0 KiB | 2.6 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.swift.org/assets/javascripts/new-javascripts/vendor/anime.iife.min.js | 74.7 KiB | 44.6 KiB |
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work
| Category | Time Spent |
|---|---|
| Other | 2.7 s |
| Script Evaluation | 321 ms |
| Style & Layout | 167 ms |
| Rendering | 43 ms |
| Parse HTML & CSS | 25 ms |
| Script Parsing & Compilation | 21 ms |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.swift.org/assets/stylesheets/new-stylesheets/application.css | 15.8 KiB | 11.2 KiB |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.
Format your HTML in a way that enables crawlers to better understand your app’s content.
Industry-standard audits powered by Google Lighthouse. — Desktop
Key metrics that affect user experience. — Desktop
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
581 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.37 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
53 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
581 ms
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
1.60 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
| URL | Resource Size | Est Savings | |
|---|---|---|---|
body > main > section#what-is-swift > div.swoop body > main > section#what-is-swift > div.swoop | www.swift.org/assets/images/landing-page/swoops/swoop-0.png | 356.3 KiB | 127.3 KiB |
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading
HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
| URL | Transfer Size | Duration |
|---|---|---|
| developer.apple.com/assets/metrics/scripts/analytics.js | 83.2 KiB | 360 ms |
| www.swift.org/assets/javascripts/new-javascripts/vendor/anime.iife.min.js | 75.3 KiB | 283 ms |
| www.swift.org/assets/javascripts/new-javascripts/application.js | 7.0 KiB | 123 ms |
| www.swift.org/assets/javascripts/new-javascripts/hero.js | 8.7 KiB | 163 ms |
| www.swift.org/assets/javascripts/new-javascripts/landing.js | 1.6 KiB | 123 ms |
| www.swift.org/assets/javascripts/new-javascripts/color-scheme-toggle.js | 3.5 KiB | 123 ms |
| www.swift.org/assets/stylesheets/new-stylesheets/application.css | 16.5 KiB | 123 ms |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| developer.apple.com/assets/metrics/scripts/analytics.js | 81.8 KiB | 26.5 KiB |
| www.swift.org/assets/javascripts/new-javascripts/hero.js | 8.0 KiB | 2.6 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.swift.org/assets/javascripts/new-javascripts/vendor/anime.iife.min.js | 74.7 KiB | 44.4 KiB |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.swift.org/assets/stylesheets/new-stylesheets/application.css | 15.8 KiB | 11.7 KiB |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.
Format your HTML in a way that enables crawlers to better understand your app’s content.
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