MBR Performance

Granular, transparent WordPress performance optimisation — full page caching, plus individual control over core features, scripts, styles, fonts, images, preloading, the database, WooCommerce and multisite.

Free, GPL-licensed, self-hosted. No telemetry, no CDN dependency for the plugin's own assets, and no account to sign up for.

Current version: 2.1.5 Requires: WordPress 5.9+ · PHP 7.4+ Tested to: WordPress 7.1 Licence: GPLv2 or later

Most performance plugins offer a single "optimise" button and hope for the best. MBR Performance does the opposite: several dozen individual optimisations, each clearly labelled, each off by default, grouped into tabs so you can enable exactly what your site needs and nothing it doesn't.

If something changes unexpectedly, you always know which switch caused it.

The finished HTML of each page is written to disk and served to subsequent visitors instead of being rebuilt. Three serving tiers, fastest first:

Each tier degrades to the next. No configuration produces an error page rather than a cache miss.

• Targeted purging. Editing a post clears that post, the front page, the blog index, every term across every taxonomy, the post type archive, the author archive, the date archives and the adjacent posts — plus the first twenty paginated pages of each. Not the whole cache.
• Query-string normalisation. Around twenty analytics and ad-click parameters (utm_*, fbclid, gclid, mc_cid, msclkid…) are stripped before lookup, so a campaign link hits the same entry as the clean URL. This is usually the difference between a 90% hit rate and a 20% one.
• Pre-compressed gzip copies written alongside each page, so the server never compresses identical bytes twice.
• X-MBR-Cache debug headers reporting HIT, MISS or BYPASS — and for a bypass, X-MBR-Cache-Reason naming the specific rule responsible.
• Never caches logged-in visitors, any page that emits a Set-Cookie header, password-protected posts, previews, search results, the WooCommerce cart/checkout/account pages, or anything marked with DONOTCACHEPAGE.
• Refuses to run alongside another page cache, naming the plugin responsible.

• Core — emojis, embeds, dashicons, heartbeat, revisions, REST hardening, HTML minification
• JavaScript — defer/async, footer moves, jQuery control, minify, combine, delayed execution, Script Modules and Interactivity API support (WP 6.5+)
• CSS — Used CSS Mode A (per page, originals deferred) and Mode B (per template, analysed sheets removed), async loading, minify, combine, paste-in Critical CSS
• Fonts — self-hosting with auto-download, subsetting, preloading, font-display strategies
• Images — WebP and AVIF conversion with bulk converter, automatic dimensions, lazy loading
• Preloading — DNS prefetch, preconnect, speculative loading, hover prefetch
• Database — revisions, transients, spam, orphaned metadata, table optimisation
• Diagnostics — Performance Doctor, self-hosted Real User Monitoring (LCP/CLS/INP), conflict detection, orphaned media, OPcache status and flushing (new in 2.1.0)

Download the latest ZIP from littlewebshack.com, then in WordPress: Plugins → Add New → Upload Plugin.

Or clone into wp-content/plugins/:

git clone https://github.com/HarbourBob/mbr-performance.git

Settings live under MBR Performance in the admin toolbar. A 45-page user guide (PDF) is bundled in the ZIP.

Tick Enable Page Caching on the Cache tab and save. That installs advanced-cache.php and adds WP_CACHE to wp-config.php for you; both are removed again when you switch caching off or deactivate the plugin.

wp-config.php is copied to wp-config.php.mbrpe-backup before it is first touched, and the edited file is syntax-checked before being written — if it doesn't parse, the original is left alone. The same applies to .htaccess.

If your host makes wp-config.php read-only, the Cache tab says so and shows the one line to add by hand. Until then caching still works, just on the slower tier.

Self-hosted. The plugin checks a manifest at raw.githubusercontent.com/HarbourBob/mbr-updates/main/mbr-performance.json and downloads releases from littlewebshack.com. Every release ZIP is SHA-256 checksummed in the manifest and verified before installation.

mbr-performance.php              bootstrap, constants, update checker
includes/
  mbrpe-bootstrap.php            module loading, defaults, migrations, activation
  class-admin.php                settings screen, tab dispatch, sanitisation
  class-page-cache.php           cache engine — cacheability, buffering, storage
  class-page-cache-dropin.php    drop-in installer, WP_CACHE, compiled config
  class-page-cache-purge.php     purge events and related-URL resolution
  class-page-cache-rules.php     .htaccess rules and Nginx snippet
  class-opcache.php              OPcache status, flush and invalidation helpers
  dropins/advanced-cache.php     the drop-in template (self-contained)
  admin/tabs/                    one file per settings tab

• Singleton modules with instance(), instantiated from MBRPE_Bootstrap::init_optimizations()
• Settings stored in one option, mbrpe_options[section][key]
• Each section gets a tab file and a sanitize_<section>_options() method
• Version-keyed migrations in maybe_upgrade(), stamped once all have run
• Text domain mbr-performance, UK English in user-facing strings

mbrpe_cache_file_path() in dropins/advanced-cache.php and MBRPE_Page_Cache::current_file_path() are deliberate near-duplicates. They can't share code — the drop-in runs before any autoloader, plugin API or options table exists.

Both carry a version marker (MBRPE_CACHE_KEY_ALGO / MBRPE_Page_Cache::KEY_ALGO). Bump both together whenever the key shape changes. A mismatch produces a silent 100% miss rate rather than a wrong page, which is safe but very easy not to notice. tools/keytest.php compares the two implementations across a matrix of request shapes and exits non-zero on any disagreement.

Issues and pull requests welcome. For anything touching the cache engine, please run php tools/keytest.php and include the result.

GPLv2 or later. See LICENSE.

Built by Robert Palmer — Little Web Shack.