0513.org

Keep the server response time for the main document short because all other requests depend on it. Learn more.

Optimized images load faster and consume less cellular data. Learn more.

Image formats like JPEG 2000, JPEG XR, and WebP often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. Learn more.

Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. Learn more.

Remove unused JavaScript to reduce bytes consumed by network activity. Learn more.

For users on slow connections, external scripts dynamically injected via `document.write()` can delay page load by tens of seconds. Learn more.

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn more

A long cache lifetime can speed up repeat visits to your page. Learn more.

The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load. Learn more.

To set budgets for the quantity and size of page resources, add a budget.json file. Learn more.

This is the largest contentful element painted within the viewport. Learn More

Lists the longest tasks on the main thread, useful for identifying worst contributors to input delay. Learn more

These DOM elements contribute most to the CLS of the page.

Meta descriptions may be included in search results to concisely summarize page content. Learn more.

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.

Add `rel="noopener"` or `rel="noreferrer"` to any external links to improve performance and prevent security vulnerabilities. Learn more.

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.

Some third-party scripts may contain known security vulnerabilities that are easily identified and exploited by attackers. Learn more.

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more

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

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

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

For ideal appearance on iOS when users add a progressive web app to the home screen, define an `apple-touch-icon`. It must point to a non-transparent 192px (or 180px) square PNG. Learn More.

The 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. Learn more.

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.

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.