3q251.com

First Meaningful Paint measures when the primary content of a page is visible. Learn more about the First Meaningful Paint metric.

Interactive elements like buttons and links should be large enough (48x48px), or have enough space around them, to be easy enough to tap without overlapping onto other elements. Learn more about tap targets.

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.

A themed splash screen ensures a high-quality experience when users launch your app from their homescreens. Learn more about splash screens. Failures: No manifest was fetched.

A maskable icon ensures that the image fills the entire shape without being letterboxed when installing the app on a device. Learn about maskable manifest icons. No manifest was fetched

The browser address bar can be themed to match your site. Learn more about theming the address bar. Failures: No manifest was fetched, No `<meta name="theme-color">` tag found.

Service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. With proper service worker and manifest implementations, browsers can proactively prompt users to add your app to their homescreen, which can lead to higher engagement. Learn more about manifest installability requirements.

Informative elements should aim for short, descriptive alternative text. Alternative text that is exactly the same as the text adjacent to the link or image is potentially confusing for screen reader users, because the text will be read twice. Learn more about the `alt` attribute.

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.

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