Lighthouse Mobile
· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.Detailed Report
Audit breakdown by category with detailed findings.
Performance
Insights
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Performance issues directly impact user engagement and conversion rates.
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
Performance issues directly impact user engagement and conversion rates.
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
| Request | Cache TTL | Transfer Size |
|---|---|---|
| www.nationaltrust.org.uk/18f5227b-e27b-445a-a53f-f845fbe69b40/stormcaster.js | 3600.0 s | 164.6 KiB |
| tms.nationaltrust.org.uk/nationaltrust/prod/Bootstrap.js | 300.0 s | 129.7 KiB |
| /js/website-cookie-preferences-vue/nt-cookie-form.full.mi... | 28800.0 s | 37.1 KiB |
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
Dog walking in bluebell woodland at Hatchlands Park, Surrey div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/visit/... | 467.3 KiB | 427.6 KiB |
A family of four walking across the grass parkland at Knole in Kent looking for… div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/kent/p... | 292.8 KiB | 253.1 KiB |
Visitors walking in bluebell woodland at Hatchlands Park, Surrey div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/surrey... | 253.1 KiB | 229.9 KiB |
Scotney Castle in spring div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/kent/p... | 268.9 KiB | 229.2 KiB |
Blossom Weekend at Ardress House, County Armagh, Northern Ireland.jpg section.sc-oeuc6o-5 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/campai... | 262.0 KiB | 214.4 KiB |
Walkers look at foliage in Lydford Gorge, Devon for the Nature equals Future ca… div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/campai... | 238.5 KiB | 198.4 KiB |
A door opening onto a sunny garden with flowers and various plants surrounding … div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/discov... | 235.7 KiB | 196.0 KiB |
Family on a wooden staircase with oil paintings on the walls, at Ham House and … div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/london... | 208.4 KiB | 168.7 KiB |
Aerial view of earthworks in the landscape at Whitesheet Hill, Wiltshire div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/wiltsh... | 175.7 KiB | 152.8 KiB |
Visitor in the bedroom at Paycocke's House and Garden, Essex div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/essex-... | 174.5 KiB | 139.3 KiB |
A woman taking photographs of the blossom at Beningbrough Hall, North Yorkshire div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/yorksh... | 162.0 KiB | 138.8 KiB |
A group of volunteers picks up litter from the beach at Penrose, Cornwall section.sc-oeuc6o-5 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/cornwa... | 176.2 KiB | 137.2 KiB |
Two visitors are looking up at an enormous, highly decorated marble fireplace i… div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/north-... | 136.3 KiB | 113.3 KiB |
Three women, dressed as blossom fairies stand underneath cherry blossom div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/visit/... | 111.8 KiB | 88.9 KiB |
Smoked mackerel fishcake in a brioche roll with gherkins and rocket section.sc-oeuc6o-5 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/discov... | 87.5 KiB | 68.1 KiB |
Black and white postcard of children wearing white dancing round a maypole div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/regions/bath-b... | 74.6 KiB | 56.3 KiB |
Honey and apple scone with jar of honey and two apple fizz drinks on the side div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/discov... | 72.3 KiB | 54.5 KiB |
White and pink blossom on a tree in spring div.sc-1xa2s2r-4 > figure.sc-17lph2-3 > picture > img | /binaries/content/gallery/website/national/library/campai... | 45.3 KiB | 34.1 KiB |
Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Duration |
|---|---|---|
| tms.nationaltrust.org.uk/nationaltrust/prod/Bootstrap.js | 129.7 KiB | 1.6 s |
HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.
Performance issues directly impact user engagement and conversion rates.
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
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.
Performance issues directly impact user engagement and conversion rates.
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.
Performance issues directly impact user engagement and conversion rates.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| nationaltrust.org.uk/ | 851 ms |
| www.nationaltrust.org.uk/ | 0.0 ms |
Diagnostics
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| /nt-front-end/_next/static/chunks/pages/_app-d691941104cf... | 1.2 MiB | 568.6 KiB |
| tms.nationaltrust.org.uk/nationaltrust/prod/Bootstrap.js | 129.2 KiB | 128.2 KiB |
| tms.nationaltrust.org.uk/nationaltrust/prod/Bootstrap.js | 129.2 KiB | 95.2 KiB |
| /nt-front-end/_next/static/chunks/framework-23ec7355c2fec... | 87.2 KiB | 44.4 KiB |
| www.nationaltrust.org.uk/18f5227b-e27b-445a-a53f-f845fbe69b40/stormcaster.js | 164.4 KiB | 40.1 KiB |
| /nt-front-end/_next/static/chunks/main-06232a913dd19e0d.js | 43.6 KiB | 21.3 KiB |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
Performance issues directly impact user engagement and conversion rates.
| URL | Total CPU Time | Script Evaluation | Script Parse |
|---|---|---|---|
| /nt-front-end/_next/static/chunks/pages/_app-d691941104cf... | 950 ms | 639 ms | 284 ms |
| /nt-front-end/_next/static/chunks/framework-23ec7355c2fec... | 872 ms | 615 ms | 27 ms |
| tms.nationaltrust.org.uk/nationaltrust/prod/Bootstrap.js | 519 ms | 366 ms | 148 ms |
| www.nationaltrust.org.uk/ | 437 ms | 15 ms | 2.3 ms |
| www.nationaltrust.org.uk/18f5227b-e27b-445a-a53f-f845fbe69b40/stormcaster.js | 343 ms | 261 ms | 31 ms |
| Unattributable | 258 ms | 6.7 ms | 0.0 ms |
| /nt-front-end/_next/static/chunks/main-06232a913dd19e0d.js | 114 ms | 95 ms | 16 ms |
| /js/website-cookie-preferences-vue/nt-cookie-form.full.mi... | 83 ms | 56 ms | 9.6 ms |
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
Performance issues directly impact user engagement and conversion rates.
| Category | Time Spent |
|---|---|
| Script Evaluation | 2.1 s |
| Script Parsing & Compilation | 524 ms |
| Other | 449 ms |
| Style & Layout | 391 ms |
| Rendering | 78 ms |
| Parse HTML & CSS | 74 ms |
| Garbage Collection | 18 ms |
Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache
Performance issues directly impact user engagement and conversion rates.
| Failure reason | Failure type |
|---|---|
| Pages with cache-control:no-store header cannot enter back/forward cache. | Actionable |
| Pages whose main resource has cache-control:no-store cannot enter back/forward cache. | Not actionable |
| Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header. | Not actionable |
Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| .klMTwz { display: flex; flex-wrap: wrap; flex: 0 1 auto; margin: 0px -0.5rem; padding: 0px; } … | 17.8 KiB | 2.2 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.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| .klMTwz { display: flex; flex-wrap: wrap; flex: 0 1 auto; margin: 0px -0.5rem; padding: 0px; } … | 17.8 KiB | 10.8 KiB |
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Performance issues directly impact user engagement and conversion rates.
More information about the performance of your application. These numbers don't directly affect the Performance score.
Accessibility
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.
ARIA
Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn how to match ARIA attributes to their roles.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Cookies on nationaltrust.org.uk
This website uses cookies. Some are essential … body.v--modal-block-scroll > div.cookie-preferences-forms > div.v--modal-overlay |
ARIA dialog elements without accessible names may prevent screen readers users from discerning the purpose of these elements. Learn how to make ARIA dialog elements more accessible.
Informational: a Permissions-Policy directive showing feature -> allowed origins.
Source: MDN Permissions-Policy
| Failing Elements |
|---|
Cookies on nationaltrust.org.uk
This website uses cookies. Some are essential … div.v--modal-overlay > div.v--modal-background-click > div.v--modal-box > div#cookieOptions |
These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.
Best Practices
General
Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.
Performance issues directly impact user engagement and conversion rates.
SEO
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.