51ad.com Site Title

深圳APP开发-微信开发-政采商城开发-深圳政府采购中心网上商城API开发-网站建设-无忧广告网

51ad.com Meta Description

无忧广告网—微信开发、APP开发、深圳政采商城开发、API开发、网站建设、网络安全。22年持续服务，更值得信任！服务热线：0755-28887771

51ad.com Test Results

51ad.com Mobile Performance: 75/100
Quick overview:
Time to Interactive
4.6 s
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.
Max Potential First Input Delay
130 ms
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.
First Meaningful Paint
2.1 s
First Meaningful Paint measures when the primary content of a page is visible. Learn more about the First Meaningful Paint metric.
Diagnostics
More information about the performance of your application. These numbers don't directly affect the Performance score.
Reduce unused CSS
Potential savings of 29 KiB
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.
Minimize main-thread work
3.0 s
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
Avoid multiple page redirects
Potential savings of 630 ms
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Largest Contentful Paint element
4,010 ms
This is the largest contentful element painted within the viewport. Learn more about the Largest Contentful Paint element
Defer offscreen images
Potential savings of 148 KiB
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.
Efficiently encode images
Potential savings of 935 KiB
Optimized images load faster and consume less cellular data. Learn how to efficiently encode images.
Serve images in next-gen formats
Potential savings of 1,809 KiB
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.
Eliminate render-blocking resources
Potential savings of 850 ms
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.
Avoid enormous network payloads
Total size was 2,752 KiB
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Avoid `document.write()`
For users on slow connections, external scripts dynamically injected via `document.write()` can delay page load by tens of seconds. Learn how to avoid document.write().
Avoid an excessive DOM size
1,244 elements
A large DOM will increase memory usage, cause longer style calculations, and produce costly layout reflows. Learn how to avoid an excessive DOM size.
Properly size images
Potential savings of 204 KiB
Serve images that are appropriately-sized to save cellular data and improve load time. Learn how to size images.
Serve static assets with an efficient cache policy
98 resources found
A long cache lifetime can speed up repeat visits to your page. Learn more about efficient cache policies.
Image elements do not have explicit `width` and `height`
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Minify CSS
Potential savings of 5 KiB
Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.
Preload Largest Contentful Paint image
If the LCP element is dynamically added to the page, you should preload the image in order to improve LCP. Learn more about preloading LCP elements.

51ad.com Mobile SEO: 92/100
Quick overview:
Crawling and Indexing
To appear in search results, crawlers need access to your app.
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

51ad.com Mobile Best Practices: 52/100
Quick overview:
General
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 deprecated APIs
1 warning found
Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.
Trust and Safety
Does not use HTTPS
1 insecure request found
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.
User Experience
Displays images with incorrect aspect ratio
Image display dimensions should match natural aspect ratio. Learn more about image aspect ratio.
Serves images with low resolution
Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.
Browser Compatibility
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. Document contains a `doctype` that triggers `limited-quirks-mode`
51ad.com Mobile Accessibility: 58/100
Quick overview:
Tables and lists
These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.
Definition list items are not wrapped in `<dl>` elements
Definition list items (`<dt>` and `<dd>`) must be wrapped in a parent `<dl>` element to ensure that screen readers can properly announce them. Learn how to structure definition lists correctly.
Navigation
These are opportunities to improve keyboard navigation in your application.
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.
Best practices
These items highlight common accessibility best practices.
`[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.
Names and labels
These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.
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.
Internationalization and localization
These are opportunities to improve the interpretation of your content by users in different locales.
`<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.
Contrast
These are opportunities to improve the legibility of your content.
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.
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