User Experience Performance Single Region Diagnostic Results

Webpage: https://www.saitebattery.vn

Device: Desktop Computer

Region: Japan (Tokyo)

Single Region Score

48
Poor Page Performance
A total of 27 improvements can achieve a better score
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].

Avoid serving legacy JavaScript to modern browsers

Polyfills and transforms enable legacy browsers to use new JavaScript features. However, many aren't necessary for modern browsers. For your bundled JavaScript, adopt a modern script deployment strategy using [module/nomodule feature detection] to reduce the amount of code shipped to modern browsers, while retaining support for legacy browsers. [Learn how to serve modern JavaScript]

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.

Properly size images

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

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]

Page lacks the HTML doctype, thus triggering quirks-mode

Specifying a doctype prevents the browser from switching to quirks-mode. [Learn more about the doctype declaration].

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]

Minify CSS

Minifying CSS files can reduce network payload sizes. [Learn how to minify CSS].

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].

Largest Contentful Paint element

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

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].

Does not use HTTPS

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].

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].

Avoid multiple page redirects

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

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].

`[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].

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].

Third parties

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

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].

Efficiently encode images

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

Uses deprecated APIs

Deprecated APIs will eventually be removed from the browser. [Learn more about deprecated APIs].

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]

Max Potential First Input Delay

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].

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].

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.

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].

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

Screen readers require list items (`

  • `) to be contained within a parent `
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