Science Knowings: HTML Course For Social Media

HTML5 Application Cache

HTML5 Application Cache

We've just covered HTML5 Web Workers, which allow us to run scripts in parallel. Now, let's dive into HTML5 Application Cache, a powerful feature that enhances offline browsing.

What is HTML5 Application Cache?

HTML5 Application Cache is a browser feature that allows web applications to cache files for offline use. This means users can access your web app even when they don't have an internet connection.

Benefits of Using HTML5 Application Cache

Using HTML5 Application Cache offers several benefits:

  • Improved user experience: Users can access your web app offline, ensuring a seamless experience.
  • Reduced data usage: Cached files don't need to be downloaded again, saving data and improving load times.
  • Increased reliability: Your web app can be accessed even in areas with poor or no internet connectivity.

How Does HTML5 Application Cache Work?

HTML5 Application Cache works by creating a manifest file that lists the files to be cached. When a user visits your web app, the browser checks the manifest and downloads the listed files. These files are then stored in the browser's cache and can be accessed offline.

Creating a Manifest File

To create a manifest file, use the <html> element with the manifest attribute. The attribute value should be the URL of the manifest file (<html manifest="manifest.appcache">)


Inside the manifest file, list the files to be cached, using the CACHE section and the NETWORK section to specify files that should only be accessed online.

Adding the Manifest File to Your HTML Page

Once you have created the manifest file, you need to link it to your HTML page using the <link> element with the rel attribute set to manifest (<link rel="manifest" href="manifest.appcache">).

Testing Your HTML5 Application Cache

To test your HTML5 Application Cache, open your web app in a browser that supports it (e.g., Chrome, Firefox). Disconnect your internet connection and reload the page. If the app loads successfully, your cache is working.

Troubleshooting HTML5 Application Cache Issues

If you encounter issues with your HTML5 Application Cache, check the following:

  • Manifest file: Ensure the manifest file is correctly formatted and linked to your HTML page.
  • Network connectivity: Verify that your internet connection is disconnected when testing offline access.
  • Browser support: Confirm that the browser you're using supports HTML5 Application Cache.

Next Up: HTML5 Server-Sent Events

In our next session, we'll explore HTML5 Server-Sent Events (SSE), a powerful technology for real-time communication between a server and a web page. Follow us for updates!