Webpage: http://www.casumina.com
Device: Desktop Computer
Region: Japan (Tokyo)
Single Region Score
Layout shifts occur when elements move absent any user interaction. [Investigate the causes of layout shifts], such as elements being added, removed, or their fonts changing as the page loads.
Image display dimensions should match natural aspect ratio. [Learn more about image aspect ratio].
Minifying JavaScript files can reduce payload sizes and script parse time. [Learn how to minify JavaScript].
Meta descriptions may be included in search results to concisely summarize page content. [Learn more about the meta description].
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].
Serve images that are appropriately-sized to save cellular data and improve load time. [Learn how to size images].
Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. [Learn how to make links accessible].
Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. [Learn how to eliminate render-blocking resources].
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].
When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. [Learn how to make buttons more accessible].
Optimize LCP by making the LCP image [discoverable] from the HTML immediately, and [avoiding lazy-loading]
Largest Contentful Paint marks the time at which the largest text or image is painted. [Learn more about the Largest Contentful Paint metric]
Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. [Learn more about modern image formats].
Minifying CSS files can reduce network payload sizes. [Learn how to minify CSS].
Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. [Learn how to provide responsive images].
Third party code can significantly impact load performance. [Reduce and defer loading of third party code] to prioritize your page's content.
Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes. [Learn more about text compression].
This is the largest contentful element painted within the viewport. [Learn more about the Largest Contentful Paint element]
Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.
Make sure that you redirect all HTTP traffic to HTTPS in order to enable secure web features for all your users. [Learn more].
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. [Learn more about the `alt` attribute].
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. [Learn how to reduce unused JavaScript].
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].
All sites should be protected with HTTPS, even ones that don't handle sensitive data. This includes avoiding [mixed content], where some resources are loaded over HTTP despite the initial request being served over HTTPS. HTTPS prevents intruders from tampering with or passively listening in on the communications between your app and your users, and is a prerequisite for HTTP/2 and many new web platform APIs. [Learn more about HTTPS].
Optimized images load faster and consume less cellular data. [Learn how to efficiently encode images].
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. [Learn how to make links crawlable]
Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. [Learn more about the viewport meta tag].
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. [Learn more about this errors in console diagnostic audit]
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. [Learn more about robots.txt].
Chrome is moving towards a new experience that allows users to choose to browse without third-party cookies. [Learn more about third-party cookies].
Consider lazy-loading offscreen and hidden images after all critical resources have finished loading to lower time to interactive. [Learn how to defer offscreen images].
These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to [windowing]. [Learn how to improve CLS]
Low-contrast text is difficult or impossible for many users to read. [Learn how to provide sufficient color contrast].