In-Browser Cache

FAQ

How is this different from other caching plugins?

Most WordPress caching plugins focus on server-side caching, which reduces server load but doesn’t help after content is delivered to the browser. In-Browser Cache operates entirely on the client-side, using modern browser capabilities to cache assets directly in the user’s browser, reducing network requests and improving page load times on repeat visits.

Does this work with other caching plugins?

Yes! In-Browser Cache complements server-side caching plugins. You can use both together for maximum performance benefits.

Will this work on all browsers?

The plugin requires browsers that support Service Workers. This includes all modern browsers (Chrome, Firefox, Safari, Edge), but not older browsers like Internet Explorer. On unsupported browsers, the plugin gracefully degrades – your site will function normally, just without the caching benefits.

Does this require HTTPS?

Yes, Service Workers only work on secure origins (HTTPS). This is a security requirement imposed by browsers, not a limitation of the plugin.

Does this work if WordPress is installed in a subdirectory?

No, this plugin requires WordPress to be installed at the root of your domain (e.g., https://example.com/) and will not work properly if WordPress is installed in a subdirectory (e.g., https://example.com/blog/).

This limitation exists because Service Workers have a scope restriction – they can only control pages within their own directory and subdirectories. Since the service worker is served from the root path (/service-worker.js), it can only cache resources for the entire domain when WordPress is at the root level.

If your WordPress installation is in a subdirectory, the plugin will appear to install successfully but caching will not function properly.

Will this slow down my site?

No, the plugin is designed with performance in mind. The service worker registration is asynchronous and doesn’t block page rendering. The caching itself improves performance by reducing network requests on subsequent page loads.

How can I clear the cache?

You can clear the cache from the plugin settings page by clicking the «Clear Cache» button. This sends a message to the service worker to delete all cached assets.

Can I exclude certain files from being cached?

Currently, the plugin uses predefined rules based on file types and URL patterns. Custom exclusion rules will be added in a future update.

How accurate are the metrics?

The metrics are collected directly from the browser and represent actual cache hits, misses, and bandwidth savings. However, they rely on the browser reporting accurate content-length headers, which may not always be available.

Why is caching disabled for logged-in users?

By default, the plugin disables caching for logged-in users to ensure GDPR compliance and protect user privacy. When users are authenticated, their browsing patterns and personal data should not be stored in browser caches without explicit consent. You can disable this feature in the plugin settings, but it’s recommended to keep it enabled for privacy compliance.

What happens when a user logs in?

When a user logs in, the service worker is automatically unregistered and all cached data is cleared. This ensures no data from the non-authenticated session persists into the authenticated session. The service worker will be re-registered when the user logs out.

How does CDN detection work?

The plugin provides comprehensive CDN support through two complementary approaches: 1) Passive CDN Recognition – automatically detects CDN assets using domain patterns for popular CDNs like Cloudflare, jsDelivr, unpkg, and others, HTTP response headers such as cf-ray, x-served-by, and server headers, and heuristic analysis of domains containing keywords like ‘cdn’, ‘static’, or ‘assets’. 2) Active CDN Support – proactively monitors CDN health and implements fallback mechanisms for enhanced reliability. No configuration is required – both detection and monitoring work automatically.

Which CDN providers are supported?

The plugin provides comprehensive support for the four major CDN providers: Cloudflare, BunnyCDN, Fastly, and Amazon CloudFront. These are detected through both domain patterns and HTTP headers for maximum accuracy. Additionally, the plugin recognizes jsDelivr, unpkg, Google Fonts, Bootstrap CDN, and many others. It also uses intelligent heuristics to detect unknown CDNs based on domain patterns. The plugin combines passive detection with active monitoring to work with any CDN while providing enhanced reliability and fallback capabilities.

Can I see separate metrics for CDN vs origin assets?

Yes! The dashboard displays separate statistics for CDN and origin assets, including cache hits, misses, and performance metrics. This helps you understand how much your CDN usage is contributing to your site’s performance improvements.

Does CDN caching work with any CDN provider?

Yes, both the passive CDN detection and active CDN support work with any CDN provider. While the plugin has specific recognition for popular CDNs, it uses intelligent heuristics to detect and cache assets from any CDN, ensuring optimal performance regardless of your CDN choice. The plugin provides both automatic detection and proactive monitoring for enhanced reliability.

I’m getting a 404 error for /service-worker.js on my Nginx server

If you’re using Nginx and getting a 404 error when trying to access /service-worker.js, you need to add a custom Nginx rule to handle this file specially. Add the following to your Nginx server configuration:

location = /service-worker.js {
    try_files $uri /index.php$is_args$args;
}

This rule ensures that requests for /service-worker.js are properly passed to WordPress for processing instead of being handled as a static file. Make sure to reload your Nginx configuration after adding this rule.