Webpage: https://toanthang.vn
Device: Desktop Computer
Region: United States East (Virginia)
Single Region Score
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]
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].
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. [Learn how to reduce unused JavaScript].
This is the largest contentful element painted within the viewport. [Learn more about the Largest Contentful Paint element]
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].
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].
Image display dimensions should match natural aspect ratio. [Learn more about image aspect ratio].
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].
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].
A large DOM will increase memory usage, cause longer [style calculations], and produce costly [layout reflows]. [Learn how to avoid an excessive DOM size].
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
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].
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]
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].
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].
Deprecated APIs will eventually be removed from the browser. [Learn more about deprecated APIs].
Low-contrast text is difficult or impossible for many users to read. [Learn how to provide sufficient color contrast].
Third party code can significantly impact load performance. [Reduce and defer loading of third party code] to prioritize your page's content.
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].