User Experience Performance Single Region Diagnostic Results

Webpage: https://www.victronenergy.com

Device: Desktop Computer

Region: United States West (Oregon)

Single Region Score

47
Poor Page Performance
A total of 19 improvements can achieve a better score
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].

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].

Background and foreground colors do not have a sufficient contrast ratio.

Low-contrast text is difficult or impossible for many users to read. [Learn how to provide sufficient color contrast].

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].

Efficiently encode images

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

`<html>` element does not have a `[lang]` attribute

If a page doesn't specify a `lang` attribute, a screen reader assumes that the page is in the default language that the user chose when setting up the screen reader. If the page isn't actually in the default language, then the screen reader might not announce the page's text correctly. [Learn more about the `lang` attribute].

Largest Contentful Paint element

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

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]

Avoid large layout shifts

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]

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

Screen readers require list items (`

  • `) to be contained within a parent `
    • Properly size images

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

    `[user-scalable="no"]` is used in the `<meta name="viewport">` element or the `[maximum-scale]` attribute is less than 5.

    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].

    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].

    Displays images with incorrect aspect ratio

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

    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].

    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 do not have descriptive text

    Descriptive link text helps search engines understand your content. [Learn how to make links more accessible].

    robots.txt is not valid

    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].

    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].

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