Edge Caching: The Secret Weapon to Boost Your WordPress Site Performance
Edge caching is a technique that uses a network of distributed edge servers to store and serve website content closer to users, reducing the time it takes to fetch data from the origin server [1]. By caching static and dynamic content at the edge, subsequent requests can be served directly from the edge server, bypassing the origin server and improving website performance [1].
WordPress websites serve a mix of static and dynamic content, making them well-suited for edge caching strategies [1]. However, proper cache invalidation is needed to avoid serving stale content [1]. Kinsta integrates with Cloudflare to provide free edge caching for all plans, automatically clearing the edge cache when content is updated [1] [3]. To enable edge caching with Kinsta, you can do so in the MyKinsta dashboard or create a Cloudflare Page Rule [1] [3].
What is Edge Caching?
Edge Caching Explained
Edge caching combines traditional caching methods and edge computing infrastructure to store data as close to the user as possible, reducing network latency [3]. It uses specialized edge servers located near the ‘fringe’ of the network to cache high-demand content locally [5]. When a request is made, the edge server serves the cached data quickly, eliminating the need to fetch it from a distant central server [5]. This reduces latency and network load, improving performance and reliability [5].
Edge caching reduces the physical distance between a website’s visitors and the origin server by storing copies of website content at edge servers closer to the users [1]. This reduces the time it takes to fetch data from the origin server, decreasing load times, reducing latency, and improving overall performance [1] [3].
- Edge Caching Infrastructure
- Edge caching uses a CDN’s network of edge servers to store and serve website content closer to users [1].
- Edge servers cache static and dynamic content, serving it directly to users instead of retrieving it from the origin server [1].
- This reduces the load on the origin server and minimizes the distance data needs to travel [1].
- How Edge Caching Works
- When a user requests a page, the request is first checked against the edge cache [3].
- If the page is not cached, it is generated dynamically by WordPress and then stored in the edge cache for future requests [3].
- Kinsta’s edge caching integrates with their local WordPress caching, so clearing the local cache also clears the edge cache [3].
By caching content closer to users, edge caching significantly improves website performance, especially for global audiences [3].
How Edge Caching Works
Edge Caching Infrastructure
Kinsta provides edge caching through its integration with Cloudflare’s network of 260+ edge servers around the world [3]. These edge servers are located closer to users, reducing the distance data needs to travel from the origin server [1].
- When a user requests a WordPress page, the request is first checked against the edge cache [3].
- If the page is not cached, it is generated dynamically by WordPress and then stored in the edge cache for subsequent requests [3].
- Subsequent requests for that page will be served directly from the edge cache until it is cleared, bypassing the origin server [3] [1].
Cache Management
Kinsta’s edge caching is integrated with their local WordPress caching, ensuring cache consistency [3]. Clearing the local cache will also clear the edge cache, preventing outdated content from being served [3] [1].
Proper cache invalidation mechanisms are crucial for WordPress sites, which serve a mix of static and dynamic content [1]. Some plugins and themes may introduce complexities, requiring careful cache management [1].
Performance Benefits
Edge caching can provide significant performance improvements for WordPress sites. Testing by Kinsta showed an average 48.6% reduction in time to first byte (TTFB) and an average 54.4% reduction in full page load times when using edge caching [3]. Cached content is served from the closest edge server, reducing data transfer distance and latency, resulting in lightning-fast load times [8].
Benefits of Edge Caching
Performance Improvements
Edge caching can significantly improve website performance by reducing latency and load times. Kinsta’s testing showed that edge caching can reduce Time to First Byte (TTFB) by an average of 48.6% and reduce full page load times by 54.4% compared to just using local caching [3]. For websites with global audiences, the performance improvements were even more dramatic, with TTFB reduced by up to 83.6% and full page load times reduced by up to 85.6% when connecting from the US to Kinsta’s data centers in Singapore, Sydney, and Melbourne [3].
Reduced Bandwidth and Cost Savings
By caching content at the edge, closer to users, edge caching decreases the amount of data that needs to be transferred from the origin server, leading to significant reductions in bandwidth usage and associated costs [5].
Enhanced User Experience
Edge caching enables faster, more reliable, and more consistent digital experiences, especially for real-time applications [5]. It also allows for efficient scaling to meet fluctuating demand, which is crucial for websites with sudden traffic spikes [9].
Improved Security
Edge servers can cache static content and perform security checks closer to the user, reducing the attack surface of the origin server [9]. This enhances the overall security posture of the website.
Websites Suited for Edge Caching
Static Websites
Static websites such as blogs, portfolios, landing pages, and informational websites are well-suited for edge caching [1]. Since their content is primarily static and infrequently updated, edge caching can significantly improve performance by serving cached versions from edge servers closer to users [1].
Interactive Applications
Interactive applications like ecommerce platforms, social media sites, and websites with dynamic content can also benefit from edge caching [1]. While proper cache invalidation mechanisms are crucial to avoid serving stale content, edge caching can still provide substantial performance gains for these types of websites [1].
Demanding and High-Resource Websites
Websites that are resource-intensive or have high traffic demands, such as streaming platforms, online gaming sites, and online learning platforms, are well-suited for edge caching [1]. Edge caching can help offload traffic from the origin server, ensuring consistent performance even during peak usage periods [1].
Promoted contents:
In summary, a wide range of websites can benefit from edge caching, including static sites, interactive applications, ecommerce platforms, media streaming sites, gaming platforms, online learning platforms, and blogs/news/informational websites [1]. However, websites with highly dynamic or real-time content, personalized content, complex caching rules, very large files, or stringent security/privacy requirements may not be as well-suited for edge caching [1].
Scenarios Where Edge Caching May Not Work Well
Limitations of Edge Caching
- Capacity Constraints: The amount of data and content that can be cached at the edge is limited by the capacity of edge servers and devices [7]. This can pose challenges for websites with large amounts of content or high-resolution media files.
- Frequently Changing Content: If the data or content being cached frequently changes, the cache can become obsolete quickly [7]. Implementing cache-invalidation techniques and expiration times can help mitigate this issue, but it adds complexity to the infrastructure [7].
- Dynamic and Personalized Content: Highly dynamic or real-time content may not be suitable for edge caching, as the content changes frequently, and caching may not be practical [1]. Personalized content tailored to individual users is also not well-suited for edge caching, as the content is unique to each user [1].
Increased Complexity and Potential Issues
- Existing Caching Rules: Implementing edge caching can introduce additional complexity, especially if the website already has complex caching rules in place [1]. Mismatched caching configurations between the origin server and edge servers can lead to cache conflicts or out-of-date content [1].
- Large File Caching: Very large files, such as high-definition videos or large datasets, may be difficult to cache effectively at the edge servers due to their size and bandwidth requirements [1].
- Security and Privacy Concerns: Edge caching can raise security and privacy concerns, as it increases the risk of unauthorized access and data breaches by storing sensitive information at the edge servers [1].
For Kinsta users specifically, edge caching may not work well with certain settings, such as geolocation-based content, password protection, and Kinsta’s Mobile Caching feature [1].
Edge Caching with Kinsta
Enabling Edge Caching with Kinsta
Kinsta integrates with Cloudflare to provide free edge caching for all its plans, making it easy to enable and manage through the MyKinsta dashboard [1] [10]. Edge caching is enabled by default for all new WordPress sites created in the MyKinsta dashboard, and can be enabled for existing sites with a single click [3] [10].
To enable edge caching for your WordPress site:
- Log in to your MyKinsta dashboard.
- Navigate to the “WordPress Sites” section and select your site.
- Click on the “Edge Caching” option.
- Click the “Enable” button to turn on edge caching for your site [10].
Automatic Cache Management
Kinsta automatically clears the edge cache when content is updated, ensuring that visitors always receive the latest version of your site [1] [10]. Additionally, Kinsta’s edge caching excludes private or personalized pages by default, preventing sensitive information from being cached at the edge [1].
Mobile-Specific Caching
Kinsta offers the ability to enable a separate mobile-specific cache for websites that generate unique markup for mobile devices [3]. This feature can be enabled alongside edge caching to further optimize performance for mobile users.
Testing and Limitations
To verify if edge caching is working correctly, you can check the HTTP headers using Kinsta’s HTTP status checker, your browser’s developer tools, or the curl command [10]. However, it’s important to note that edge caching has some limitations, such as not respecting narrow-scope geolocation cache variations, not being compatible with custom cache exclusions, and not serving static assets (which can be handled by Kinsta CDN) [10].
Enabling Edge Caching
Enabling Edge Caching with Kinsta
Kinsta integrates with Cloudflare to provide free edge caching for all its plans, making it easy to enable and manage through the MyKinsta dashboard [1]. To enable edge caching for your WordPress site:
- Log in to your MyKinsta dashboard.
- Navigate to the “WordPress Sites” section and select your site.
- Click on the “Edge Caching” option.
- Click the “Enable” button to turn on edge caching for your site [1].
Alternatively, you can create a Cloudflare Page Rule to enable edge caching for your WordPress site hosted on Kinsta [1].
Edge Caching on WordPress.com
WordPress.com has introduced a feature called ‘Global Edge Cache’ that automatically makes WordPress sites load faster for visitors around the world by leveraging their global network of data centers [2]. Global Edge Cache is always enabled on Free, Personal, and Premium WordPress.com sites, and can be enabled for Business and Commerce sites from the ‘Hosting Configuration’ page [2].
Edge Caching with Pressable
Pressable provides Edge Cache across all plans, a free performance feature that allows WordPress sites to leverage Pressable’s global network of edge servers to deliver page and static asset cache [12]. Edge Cache can be enabled/disabled via the MyPressable Control Panel or directly from the WordPress admin under Settings > Edge Cache [12]. Purging the Edge Cache can be done via the MyPressable Control Panel or the WordPress admin, and the status of Edge Cache can be checked by looking at the x-ac response header [12].
FAQs
What does edge cache mean in the context of WordPress?
In WordPress, particularly on the WordPress VIP Platform, the edge cache refers to a network of servers globally distributed to enhance content delivery. These servers, part of a content delivery network (CDN), store content and serve it from a location nearest to the user. When a user first requests content, it is fetched from the origin server and then stored on the edge cache server for quicker subsequent access.
How does edge caching work?
Edge caching involves storing frequently accessed data on servers that are closer to the users who need that data. This strategy is employed to decrease the latency caused by long-distance data transmission, which can otherwise slow down the performance of applications. By using edge caching, applications can perform better and offer a more satisfying user experience.
Is it necessary to use a cache plugin for WordPress?
Yes, employing a caching plugin in WordPress is a straightforward method to enhance your site’s speed. A caching plugin works by saving parts of your website, such as static HTML, CSS, and JavaScript files, directly on your server. This allows these elements to be served faster to users, significantly speeding up your site.
What is Kinsta’s edge caching service?
Kinsta offers an Edge Caching service where the pages of your site cached at a local data centre are then distributed across Kinsta’s network. This distribution enables faster delivery of cached HTML pages to visitors around the world, reducing the load on your server by decreasing the number of server requests.
References
[1] – https://kinsta.com/blog/edge-caching-wordpress/[2] – https://wordpress.com/blog/2023/07/13/global-edge-cache/
[3] – https://kinsta.com/blog/edge-caching/
[4] – https://www.cloudways.com/blog/introducing-edge-page-caching/
[5] – https://www.evoquedcs.com/blog/edge-caching-to-enhance-application-performance
[6] – https://www.serverwatch.com/guides/edge-cache/
[7] – https://www.harperdb.io/post/edge-caching-explained-why-you-should-be-using-it
[8] – https://www.linkedin.com/pulse/make-your-site-faster-wordpress-global-edge-cache-sajid-ahmed
[9] – https://www.quora.com/What-benefits-can-edge-servers-bring-to-global-website-performance
[10] – https://kinsta.com/docs/wordpress-hosting/caching/edge-caching/
[11] – https://community.cloudflare.com/t/kinsta-edge-caching/443321
[12] – https://pressable.com/knowledgebase/edge-cache/