How to correctly implement browser caching for pagespeed insights?

@dortha 

Implementing browser caching is an important factor for improving website performance and optimizing pagespeed insights. Here are the steps to correctly implement browser caching:

1. Set an appropriate expiration time: Set an appropriate expiration time for each resource, so the browser knows how long it should keep the resource in its cache. Generally, static resources like images, CSS, and JS files can be cached for a longer time, while dynamic resources like HTML and API responses should be cached for a shorter time.
2. Use Cache-Control Headers: Set the Cache-Control header for each resource with an appropriate value to control how the cache should behave. The two most commonly used Cache-Control headers are max-age and public.max-age: Specifies the time in seconds that the resource should be cached. For example, Cache-Control: max-age=31536000 means the resource should be cached for a year.public: Indicates that the resource can be cached by both the client and intermediary servers like proxy servers.
3. Use ETags: ETags are HTTP response headers that allow the browser to verify if a cached resource has been modified on the server. By using ETags, the browser can avoid downloading the resource again if it hasn't been modified.
4. Enable gzip compression: Enable gzip compression to reduce the size of the resources being transferred. This can significantly improve page loading speed.
5. Use a Content Delivery Network (CDN): A CDN can help improve the speed and reliability of delivering resources by caching them on servers located closer to the user.
6. Test and Monitor: Test and monitor your website regularly to ensure that the caching settings are working as intended and adjust the settings as needed.

By correctly implementing browser caching, you can improve website performance and optimize pagespeed insights scores.

@dortha 

Here is a step-by-step guide to correctly implement browser caching for Pagespeed Insights:

1. Identify the resources to cache: Determine which resources on your website should be cached, such as images, CSS files, JS files, fonts, and any other static assets.
2. Set caching headers: Configure your server to send caching headers along with the response for each resource. There are different headers you can use, but the most commonly used ones are "Cache-Control" and "Expires". a. Cache-Control: This header specifies caching rules for a specific resource. Set a "max-age" value to define the time in seconds that the resource should be cached. For example, "Cache-Control: max-age=31536000" would cache the resource for a year. b. Expires: This header specifies an absolute expiration date and time for the resource. It should be set to a date in the future. For example, "Expires: Thu, 31 Dec 2022 23:59:59 GMT" tells the browser that the resource can be cached until the end of 2022.
3. Implement ETags (optional): ETags provide a way for the browser to validate if a cached resource has changed on the server. When a resource is requested, the server sends an ETag along with the response. The ETag acts as a unique identifier for that version of the resource. If the resource hasn't changed, the server responds with a "304 Not Modified" status and the browser uses the cached version.
4. Enable gzip compression: Compressing your resources using gzip can significantly reduce their file size, leading to faster loading times. Configure your server to enable gzip compression for supported resources.
5. Utilize a Content Delivery Network (CDN): A CDN stores cached copies of your website on servers located in different geographical locations. This helps deliver resources to users faster by reducing latency. Consider using a CDN to distribute your static assets worldwide and improve performance.
6. Test and monitor: Regularly test and monitor your website's caching implementation to ensure it is working correctly. Use tools like Pagespeed Insights or web browser developer tools to check if caching headers are being sent and resources are being cached as expected.

By following these steps, you can correctly implement browser caching for Pagespeed Insights and improve your website's performance and loading speed.