APC Object Cache Backend vs Warmer – Cache Warmer and Cache Preload Crawler

APC Object Cache provides a persistent memory-based backend for the WordPress object cache. APC must be available on your PHP install. An object cache is a place for WordPress and WordPress extensions to store the results of complex operations. On subsequent loads, this data can be fetched from the cache, which will be must faster than dynamically generating it on every page load. The APC Object Cache backend is also compatible with Batcache, the powerful full page caching engine that runs on WordPress.com Be sure to read the installation instructions, as this is not a traditional plugin, and needs to be installed in a specific location.

Warmer is a WordPress cache warmer and cache preload crawler that visits your site URLs on a schedule so page cache can be generated before real visitors arrive. Most caching plugins create cached pages only after a URL is requested. That means the first visitor after a cache purge, cache expiration, deployment, or content update may hit a slower uncached page. Warmer helps solve that cold-cache problem by crawling selected URLs in the background and warming the cache ahead of time. Use Warmer to warm posts, pages, archives, media attachment pages, and supported custom post types. You control the schedule, URL sources, request delay, timeout behavior, and diagnostics from the WordPress admin. What Warmer does Warms page cache by visiting selected site URLs Preloads cache on a schedule using WordPress cron Crawls posts, pages, category archives, tag archives, media attachment pages, archives, and supported custom post types Provides manual start and stop controls Shows crawl status, success counts, failure counts, and downloadable logs Includes diagnostics for HTTP requests, URL sources, scheduler status, and server compatibility Supports automation workflows with webhooks and WP-CLI Saves settings automatically with Ajax and top-right confirmation notices Works alongside caching systems that build cache when a page is requested Why use a cache warmer? A caching plugin can make cached pages fast, but the cache usually needs to exist first. After a purge or expiration, the first real visitor may be the one who triggers cache generation. Warmer creates those first visits automatically, helping reduce cold-cache page loads and keeping important URLs ready for visitors. Warmer is useful after: Cache purges or cache expiration Publishing or updating content Theme, plugin, or deployment changes Low-traffic periods where pages may fall out of cache Scheduled maintenance Landing page, archive, and custom post type updates URL sources Choose which parts of your site should be warmed: Posts Pages Category archives Tag archives Media attachment pages Archive pages Supported custom post types Request controls Fine-tune cache warming behavior for your hosting environment: Page timeout Connection timeout Request delay Retry attempts User-Agent override Redirect handling SSL certificate verification Manual start and stop controls URL source testing Start with conservative delay and timeout settings, then adjust based on your server response time, cache behavior, and hosting limits. Logging and diagnostics Warmer includes visibility tools so you can understand what happened during each cache warming run: Crawl status tracking Success, failure, redirect, average time, and last-run statistics Structured log rows with status badges Log filters for errors, warnings, success, and redirects Search by URL, status, or message Downloadable logs Clear log history with confirmation System information Source testing Schedule status HTTP request diagnostics Compatibility Warmer is cache-plugin agnostic. It works with caching plugins, server caches, reverse proxies, and CDN/page cache layers that generate cache when a URL is visited. Common setups include: LiteSpeed Cache WP Rocket W3 Total Cache WP Super Cache NGINX FastCGI cache Varnish and reverse proxy caches CDN/page cache layers configured to cache visited pages Warmer does not replace your caching plugin. It helps your existing cache layer stay warm by requesting the pages you choose. Developer and automation features WP-CLI support for command-line cache warming workflows Webhook support for deployment and publishing workflows Diagnostics for testing URL sources and scheduler behavior Logs that make cache warming easier to monitor and debug Best use cases Warmer is built for site owners, developers, agencies, and performance-focused WordPress teams who want to reduce cold-cache page loads. It is especially helpful for: Business websites Blogs and publishers WooCommerce product pages and category pages when custom post type warming is enabled Membership and LMS sites with cacheable public content Sites using full-page cache Sites with scheduled cache expiration Sites where important pages should stay fast after cache purges