Danila Vershinin

Cacheability makes your WordPress site a better HTTP citizen, improving SEO and cache efficiency.
<h4>Free Features</h4>
Soft 404 Fix
WordPress returns HTTP 200 for empty search results, invalid tag pages, and empty category archives. Google marks these as “soft 404” errors in Search Console, hurting your SEO.
Cacheability fixes this by returning proper 404 status codes when:
<ul>
<li>Search results are empty (<code>/?s=nonexistent</code>)</li>
<li>Tag archives are empty (<code>/tag/nonexistent/</code>)</li>
<li>Category archives are empty</li>
<li>Author archives are empty</li>
</ul>
Smart Cache-Control Headers
Automatically adds <code>s-maxage</code> headers so Varnish, NGINX, and CDNs can cache your pages efficiently without affecting browser caching behavior.
<ul>
<li>Search/404 pages: 1 hour cache</li>
<li>All other pages: 1 year cache (your purge plugin handles invalidation)</li>
</ul>
<h4>Cacheability Pro</h4>
Upgrade to <a href="https://www.getpagespeed.com/web-apps/cacheability-pro" rel="nofollow ugc">Cacheability Pro</a> for advanced features:
<ul>
<li>Cache Warming — Automatically warm pages after purging so visitors never hit cold cache</li>
<li>Conditional GET (304) — Return 304 Not Modified for unchanged content, saving bandwidth</li>
<li>ESI Support — Cache pages with dynamic nonces (comments, login forms)</li>
<li>Rate-Limit Safe — Smart request queuing to avoid 429 errors</li>
<li>Sitemap Warming — Warm all pages from sitemap after full purge</li>
<li>WP-CLI Commands — <code>wp cacheability warm</code> and more</li>
<li>Priority Support — Get help when you need it</li>
</ul>
<a href="https://www.getpagespeed.com/web-apps/cacheability-pro" rel="nofollow ugc">Get Cacheability Pro →</a>

Cacheability

HTTP optimization for WordPress. Fixes soft 404 errors and adds smart cache headers.

Viktor Szépe

“It’s important to make resources (images, scripts, stylesheets, etc.) cacheable.”
<a href="http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/" rel="nofollow ugc">Steve Souders</a>
It is much easier to use a CDN without Query String Parameters. 
This plugins alters only local resources’ URL-s. 
The <code>ver</code> Query String Parameter will be inserted into the filename.
For example <code>jquery.min.js?ver=1.10</code> becomes <code>jquery.min.110.js</code>.
To reverse this in the web server add this line to your nginx config:
<pre><code>server {
 location ~ ^(.+)\.\d\d+\.(js|css|png|jpg|jpeg|gif|ico)$ {
 #try_files $uri $1.$2 /index.php?$args;
 try_files $uri $1.$2 =404;
 }
}
</code></pre>
Or to your Apache configuration or <code>.htaccess</code> file.
<pre><code>RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)\.\d\d+\.(js|css|png|jpg|jpeg|gif|ico)$ $1.$2 [NC,L]
</code></pre>
<h4>Testing the plugin before live usage</h4>
You can test the plugin by replacing the two <code>add_filter()</code> calls with this
<pre><code>require_once( dirname( dirname( dirname( dirname( __FILE__ ) ) ) ) . '/wp-load.php' );
wp();
echo o1_revving_src( $argv[1] ) . PHP_EOL;
</code></pre>
Then start it from CLI: <code>php revving.php <TEST-URL></code>
<h4>Links</h4>
Development of this plugin goes on on <a href="https://github.com/szepeviktor/resource-versioning" rel="nofollow ugc">GitHub</a>.

Resource Versioning

Turn Query String Parameters into file revision numbers.

Cacheability vs Resource Versioning