Webpage: https://osg.co.jp
Device: Desktop Computer
Region: Japan (Tokyo)
Single Region Score
Image display dimensions should match natural aspect ratio. [Learn more about image aspect ratio].
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]
Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes. [Learn more about text compression].
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]
Screen reader users rely on frame titles to describe the contents of frames. [Learn more about frame titles].
This is the largest contentful element painted within the viewport. [Learn more about the Largest Contentful Paint element]
Optimize LCP by making the LCP image [discoverable] from the HTML immediately, and [avoiding lazy-loading]
Third party code can significantly impact load performance. [Reduce and defer loading of third party code] to prioritize your page's content.
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]
Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. [Learn more about touch targets].
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]
Minifying CSS files can reduce network payload sizes. [Learn how to minify CSS].
When definition lists are not properly marked up, screen readers may produce confusing or inaccurate output. [Learn how to structure definition lists correctly].
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].
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.
Descriptive link text helps search engines understand your content. [Learn how to make links more accessible].
Low-contrast text is difficult or impossible for many users to read. [Learn how to provide sufficient color contrast].
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].
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].
Minifying JavaScript files can reduce payload sizes and script parse time. [Learn how to minify JavaScript].
Informative elements should aim for short, descriptive alternative text. Alternative text that is exactly the same as the text adjacent to the link or image is potentially confusing for screen reader users, because the text will be read twice. [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].
Deprecated APIs will eventually be removed from the browser. [Learn more about deprecated APIs].