User Experience Performance Single Region Diagnostic Results

Webpage: https://www.jvckenwood.com

Device: Desktop Computer

Region: Japan (Tokyo)

Single Region Score

43
Poor Page Performance
A total of 38 improvements can achieve a better score
Avoid an excessive DOM size

A large DOM will increase memory usage, cause longer [style calculations], and produce costly [layout reflows]. [Learn how to avoid an excessive DOM size].

Heading elements are not in a sequentially-descending order

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. [Learn more about heading order].

Image elements do not have `[alt]` attributes

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 the impact of third-party code

Third-party code can significantly impact load performance. Limit the number of redundant third-party providers and try to load third-party code after your page has primarily finished loading. [Learn how to minimize third-party impact].

Third parties

Third party code can significantly impact load performance. [Reduce and defer loading of third party code] to prioritize your page's content.

Minify JavaScript

Minifying JavaScript files can reduce payload sizes and script parse time. [Learn how to minify JavaScript].

Browser errors were logged to the console

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]

Uses third-party cookies

Chrome is moving towards a new experience that allows users to choose to browse without third-party cookies. [Learn more about third-party cookies].

Document request latency

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Eliminate render-blocking resources

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].

LCP request discovery

Optimize LCP by making the LCP image [discoverable] from the HTML immediately, and [avoiding lazy-loading]

Serve images in next-gen formats

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].

Elements with an ARIA `[role]` that require children to contain a specific `[role]` are missing some or all of those required children.

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. [Learn more about roles and required children elements].

Minimize main-thread work

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]

Properly size images

Serve images that are appropriately-sized to save cellular data and improve load time. [Learn how to size images].

Reduce unused JavaScript

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. [Learn how to reduce unused JavaScript].

Efficiently encode images

Optimized images load faster and consume less cellular data. [Learn how to efficiently encode images].

Reduce JavaScript execution time

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].

Avoid multiple page redirects

Redirects introduce additional delays before the page can be loaded. [Learn how to avoid page redirects].

Defer offscreen images

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].

Issues were logged in the `Issues` panel in Chrome Devtools

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.

Touch targets do not have sufficient size or spacing.

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].

Missing source maps for large first-party JavaScript

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].

Lists do not contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. [Learn more about proper list structure].

Links are not crawlable

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]

Does not have a `<meta name="viewport">` tag with `width` or `initial-scale`

A `` not only optimizes your app for mobile screen sizes, but also prevents [a 300 millisecond delay to user input]. [Learn more about using the viewport meta tag].

Improve image delivery

Reducing the download time of images can improve the perceived load time of the page and LCP. [Learn more about optimizing image size]

`[aria-*]` attributes do not match their roles

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].

Largest Contentful Paint element

This is the largest contentful element painted within the viewport. [Learn more about the Largest Contentful Paint element]

Displays images with incorrect aspect ratio

Image display dimensions should match natural aspect ratio. [Learn more about image aspect ratio].

Render blocking requests

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.

Links do not have a discernible name

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].

`<frame>` or `<iframe>` elements do not have a title

Screen reader users rely on frame titles to describe the contents of frames. [Learn more about frame titles].

ARIA input fields do not have accessible names

When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. [Learn more about input field labels].

List items (`<li>`) are not contained within `<ul>`, `<ol>` or `<menu>` parent elements.

Screen readers require list items (`

  • `) to be contained within a parent `
  • Buttons do not have an accessible name

    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].

    Reduce unused CSS

    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].

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