Caching Plugins For Faster Ajax In WordPress

Why Ajax Requests Get Slow in WordPress

Ajax requests in WordPress can become slow over time as the site grows in size and complexity. Multiple factors contribute to the gradual slowing down of Ajax performance:

• Increased database size – As the site database grows with more posts, comments, metadata etc. database queries take longer.
• Heavy plugins – Complex plugins making multiple database queries can slow down page load and Ajax requests.
• Too many custom fields – Large postmeta database tables affect database access time.
• High traffic – More concurrent users put a load on server resources making Ajax sluggish.
• Unoptimized code – Poorly written Ajax code, queries and functions can choke webpage speed.
• Expensive operations – On-the-fly image processing, PDF generation hurt Ajax speed.

Caching techniques help circumvent these bottlenecks drastically speeding up perceived Ajax performance by users. Instead of slower backend processes, cached data is served faster to users.

How Caching Can Speed Up Ajax

Caching avoids expensive database queries and backend computations by saving pre-generated results. Subsequently these cached artefacts are reused to handle requests faster. When caching is implemented web servers respond with cached copies instead of dynamically generating pages.

Common caching mechanisms used for accelerating Ajax are:

• Browser caching – Browsers store static assets like scripts, stylesheets, images locally on first download. Subsequent requests use these cached local copies eliminating roundtrips speeding up perceived performance.
• Page caching – Fully rendered webpages are cached as static HTML files bypassing PHP execution and database queries. Ajax pulled content from these cached pages loads blazing fast.
• Object caching – Saves frequently accessed database query results, API responses and computed data structures in memory or disks. Ajax code retrieves cached artefacts avoiding expensive regeneration.
• Content Delivery Networks – CDNs distribute cached static assets across global edge servers closer to visitors. Visitors download assets from nearby CDN edges faster through caching.

Next we recommend caching plugins that apply above strategies for optimizing Ajax requests in WordPress.

Recommended Caching Plugins for Ajax

Here are the top plugins leveraging caching to improve Ajax performance in WordPress sites of any scale:

• WP Fastest Cache – Easy-to-use caching for beginners that works out-of-the-box.
• LiteSpeed Cache – Advanced configuration for seasoned developers and sites with high traffic.
• WP Rocket – Ideal for non-technical site owners with user-friendly options.

WP Fastest Cache – Simple All-in-One Option

WP Fastest Cache is a popular free caching plugin for WordPress available from over 3 million active installs. The plugin offers a fast all-in-one solution for caching with little configuration.

It speeds up Ajax requests in WordPress through following caching mechanisms:

• HTML & Page caching – Fully rendered webpages are cached as static files. Ajax pulled content from these cached pages loads faster avoiding backend processing.
• Minification & bundling – JavaScript and CSS files are minimized & bundled together into fewer files improving performance. Browsers can cache these static assets locally.
• CDN support – Serves scripts, stylesheets and images from free CDN falling back to own servers when unavailable. Visitors enjoy CDN edge caching benefits.
• Gzip compression – Compresses HTML, JavaScript, CSS and images sent over the network reducing payload size for faster transfers.
• Database caching – WordPress Object Cache support caches database queries results avoiding frequent repetitive database queries.
• Browser caching – Cached static assets need not be downloaded again speeding up site interactions. Cache expiry times can be customized as needed.

The plugin automatically handles clearing cached files when site content changes. Stale cached copies are not served ensuring content consistency while providing best performance. Standard WordPress hooks are also available for customizing cache invalidation.

With its easy setup and configuration WP Fastest Cache is the best bet for beginners looking to enable caching quickly for faster Ajax in WordPress.

LiteSpeed Cache – Advanced Cache Customization

The LiteSpeed Cache plugin taps into the LiteSpeed web server’s powerful caching features for big performance gains. Beyond standard caching, advanced controls offered enable tweaking cache parameters for optimizing Ajax speed.

How LiteSpeed Cache improves Ajax performance:

• Page cache – Entire page output can be stored for instant reuse avoiding backend processing delays.
• Object cache – Caches database queries, external API call results reducing load for better Ajax performance.
• Browser cache – Caching static assets in visitor’s browsers prevents external resource downloading roundtrips during Ajax usage.
• Gzip compression – Compacts content before sending from server to clients saving bandwidth improving transfer speed.
• Minification – Javascript, CSS assets can be minified reducing their payload size for quicker downloads.
• CDN capabilities – Static resources served from CDN locations close to visitors improving latency perceived by end users.

Granular cache configuration options available with LiteSpeed sets it apart from other plugins:

• Cache vary support – Enables caching multiple variants of a page based on query strings, cookies, user agents etc.
• Exclude from cache – Selective exclusion for certain pages or URL patterns matching dynamic pages that shouldn’t be cached.
• Individual TTLs – Customizable time to live for browser caches, private browser caches and public CDN caches as necessary.
• WebP support – Smaller WebP images can be served instead of JPEG/PNG images where browser supports the next-gen image format.

LiteSpeed Cache needs the open-source LiteSpeed web server or LiteSpeed-based hosts for harnessing advanced caching capabilities. The hands-on control makes it suitable for experienced developers with some learning effort involved.

WP Rocket – User-Friendly Settings for Non-Techies

WP Rocket simplifies website caching configuration through an easy-to-use admin interface ideal for non-technical site owners. Underneath is the powerful WP-Optimize toolkit further enhancing caching capabilities out-of-the-box.

How WP Rocket accelerates Ajax via caching:

• Page caching – Entire pages are cached as static HTML for instant reuse eliminating backend generation time.
• Minification & concatenation – Combined, compressed assets improve transfer speed over the wire and local caching.
• Lazy loading – Images/iframes load only when needed in viewport improving initial page load avoiding layout shifts.
• Static resources as CDN – Hosts scripts, CSS and images on CDN improving caching through distributed edge servers.
• DNS prefetching – Browsers proactively perform domain name resolution improving downstream resource loading.
• Database optimization – Scheduled cleanup of database tables, optimize queries and avoid expensive calls.

Additional user-friendly optimizations relevant for Ajax speed:

• File optimization – Auto compress large images with appropriate lossy/lossless formats.
• Browser caching – Set client-side caching policies through wp-config helping local static asset caching.
• Preload cache – Preload cache on first user request preparing cache for subsequent visitors.
• Automatic cache purge – No need to manually clear cache with automatic purge on content updates.

WP Rocket offers the best of usability and efficiency for WordPress caching. Even non-techies can setup performance optimizations like pros with minimal configuration. The automatic background processes spare users from mundane cache invalidation and optimization chores. For most users WP Rocket delivers great Ajax acceleration sans complexity.

Setting up Server-Side Caching for Ajax

While plugin based caching works great, server-side caching mechanisms can further accelerate Ajax performance, reduce server loads and save hosting bills. CDNs also pitch in enhancing caching effects while offloading traffic.

Configuring Browser Caching in wp-config.php

Leveraging client-side browser caching avoids redownloading WordPress site’s static assets like scripts, stylesheets, images etc. Visitors will load assets from local disk cache without server roundtrips once cached locally saving bandwidth and latency.

Browser caching policies for static files can be defined programmatically in WordPress wp-config.php. For example:

<IfModule mod_expires.c>
ExpiresActive On 
ExpiresByType image/jpg "access plus 1 year"
ExpiresByType image/jpeg "access plus 1 year"
ExpiresByType image/gif "access plus 1 year"
ExpiresByType image/png "access plus 1 year"
ExpiresByType text/css "access plus 1 month"
ExpiresByType text/html "access plus 1 week"
ExpiresByType application/pdf "access plus 1 month"
ExpiresByType text/x-javascript "access plus 1 month"
ExpiresByType application/x-shockwave-flash "access plus 1 month"
ExpiresByType image/x-icon "access plus 1 year"
ExpiresDefault "access plus 2 days"
</IfModule>

This caches static files in visitor browsers configured for 1 week to 1 year reducing page load times on repeat visits. HTML pages are set to expire from local caches after 1 week to maintain content freshness.

Testing Ajax Speed Improvements

Verifying caching mechanisms indeed improve end-user facing Ajax performance is crucial. Following ways to measure Ajax speeds help quantify caching benefits:

• PageSpeed Insights – Provides field performance metrics and suggestions to analyse real world speeds.
• WebPageTest – Fetches pages from multiple locations providing timing metrics for optimizations.
• Chrome DevTools – Network panel helps inspect page load sequences and measure resource fetch times.
• Apache Bench (AB) – Load test tool generates concurrent requests measuring server response times under different caching modes.

Compare Ajax speeds across desktop and mobile clients from multiple locations worldwide. Check advanced metrics around first byte time, latency, requests counts and bandwidth impact. Measure average response times for Ajax requests to backend APIs with and without caching enabled. This quantifies the Ajax performance boost caching techniques provide in real world scenario.

Further Optimizations for Faster Ajax

Beyond caching, additional front-end and back-end optimizations collectively enhance Ajax speeds further:

• Enable Gzip compression on web servers for faster asset transfers minimizing bandwidth usages.
• Minify HTML/CSS/JavaScript to reduce payload sizes lowering transfer latency.
• Limit plugins only to essentials avoiding unnecessary bloat affecting page load speeds.
• Async load non-critical third-party scripts preventing them from blocking page render.
• Split code into multiple bundles downloading parallelly using browser HTTP/2 capabilities.
• Use Ajax Prefilters to modify request parameters for optimizing backend queries.
• Decrease number of DOM elements through effective markup for faster script execution.
• Set Expires headers on Nginx for enabling better browser caching of static resources.

Check out additional performance best practices for further boosting Ajax speeds in WordPress. Careful application of multifaceted optimization techniques results in snappy websites leveraging full power of caching.