The short version: One of the Joomla extensions we install on every site in our Monthly Joomla Website Management package — ochResponsiveImages — is getting a meaningful upgrade on June 2nd. Galleries and lightboxes get the same speed treatment your content images already get, big processing jobs stop crashing into PHP timeouts, and cached files now keep themselves tidy in the background.
If you're already a Cybersalt Monthly Management client and you'd like us to enable ochResponsiveImages on your site — or check the boxes for the new gallery-optimization feature once 4.2.0 lands — just reply or send us a note and we'll take care of it. The license is already part of your management package; there's nothing extra to buy.
If you're not on our management package but you run a Joomla site of your own, Ruud van Lent (the developer) is offering a 20% launch discount on new subscriptions and renewals until June 1st — €20 instead of €25, code LAUNCH420. Direct link near the bottom of this post.
Read the technical breakdown ↓
What is ochResponsiveImages and why does it matter?
Modern websites get rated on how fast they load. Google PageSpeed Insights, Core Web Vitals, your visitors' patience — they all reward sites that send the smallest possible images to each visitor's device. A 2,000-pixel-wide photo loaded on someone's phone is wasted bytes; a JPEG when their browser supports WebP or AVIF is also wasted bytes. The differences add up to seconds of load time and noticeably worse search rankings.
ochResponsiveImages handles all of that automatically. Once it's installed and turned on, every image your site serves gets quietly resized, recompressed, and converted to the most efficient format the visitor's browser supports — often 30% smaller than the original with no visible quality loss. You don't have to do anything different when you write articles or upload photos; the plugin sits in the background and does the work.
It's one of the extensions Cybersalt licenses across our entire client base as part of the pro Joomla extensions suite we include with every Monthly Joomla Website Management account.
What changes in 4.2.0
Four things, all of them practical:
1. Galleries and lightboxes get the same treatment as content images. Until now, ochResponsiveImages optimized the images embedded in your articles, but the photos in your image galleries and lightbox popups slipped through untouched. As of 4.2.0, those get converted to WebP or AVIF as well. (This feature is off by default — site owners decide when to enable it — but on most Joomla sites it's a clear win.)
2. No more blank pages during heavy processing. If you've ever rebuilt the optimized-image cache on a site with thousands of photos, you've probably hit a PHP timeout — the browser shows a white page or a 504 gateway error and you're not sure whether the job finished. The 4.2.0 release watches how much execution time is left, stops cleanly before the timeout hits, and picks up where it left off on the next request. Big processing jobs now complete instead of crash.
3. Replace an image, the cache updates itself. If you upload a new version of banner.jpg to overwrite the old one, the previously cached versions are now rebuilt automatically. No more "why is the old image still showing?" head-scratching, no more manual cache clears.
4. Automatic cache cleanup in the background. A new task-scheduler plugin scans for cached files that no longer correspond to anything on the site and removes them quietly. One less thing to think about, and one less folder that grows endlessly.
What this means for Cybersalt-managed sites
Our Monthly Management subscribers don't need to do anything — when 4.2.0 ships on June 2nd we'll roll it out across the sites we manage as part of our standard maintenance pass. If you're not currently using ochResponsiveImages on your site and you'd like us to install it, just let us know. The license cost is already part of what your management subscription covers.
If you've been on the fence about whether your site needs this kind of optimization, the short answer is: if Google PageSpeed Insights is telling you that "serve images in next-gen formats" or "properly size images" is hurting your score, ochResponsiveImages will quietly fix both of those without you having to think about it again.
If you'd like to subscribe yourself
Site owners who aren't on our management package can subscribe to ochResponsiveImages directly from Ruud's site. Until midnight on June 1st he's offering 20% off — €20 for a year instead of the regular €25 — using the coupon code LAUNCH420. The same coupon also works on renewals if you're an existing subscriber.
Subscribe link (the discount code is pre-applied):
https://onlinecommunityhub.nl/subscribe-now/ochresponsiveimages-12-months?coupon=LAUNCH420
For a closer look at the extension itself before you buy, the product page is at onlinecommunityhub.nl/joomla-extensions/ochresponsiveimages.
The technical breakdown
For the more technically inclined — what's actually going on under the hood, and why these four changes matter on a working production site.
WebP, AVIF, and the <picture> element
ochResponsiveImages works by transparently rewriting the image markup in your rendered HTML. When a visitor's browser requests a page, the plugin intercepts each image reference and emits a <picture> element with multiple <source> children — one per format (AVIF, WebP, original JPEG/PNG fallback) and per breakpoint (mobile, tablet, desktop, retina). The browser then picks the smallest file it can render. On a modern Chrome or Firefox, that's almost always the AVIF, which can be 30–50% smaller than the equivalent JPEG.
The plugin also injects width and height attributes plus decoding="async" on every image. Both of those help with Core Web Vitals: width/height prevent the cumulative layout shift (CLS) penalty when an image pops in mid-render, and decoding="async" stops image decoding from blocking the main thread on long pages.
Gallery and lightbox coverage — what changed
Up to 4.1.x, the plugin walked the rendered HTML looking for <img> tags inside article content. Gallery and lightbox extensions (Ignite Gallery, Droppics, sigplus, the JCE Pro MediaBox, plenty of others) often defer the actual <img> emission to JavaScript or build their HTML inside containers that the plugin's article-level walker didn't enter. 4.2.0 extends the rewriter to those container patterns, so the same <picture> + srcset treatment is applied across gallery markup as well.
The feature ships disabled because gallery layouts are more sensitive to dimension hints than free-flowing article images — turning it on for a site that builds galleries via inline-styled <img> tags with hard-coded widths can sometimes need a few CSS tweaks. Cybersalt will be testing this on our staging copies before flipping it on across the managed-site fleet.
Execution-time-aware batch processing
Image conversion is CPU-bound. On a site with several thousand images, the initial cache-build pass can comfortably exceed PHP's max_execution_time (typically 30–120 seconds on shared hosting). The old behaviour was to hit the limit, surface a white page or a 504, and leave the cache half-built — meaning the next page render would trip into the same conversion attempt and time out again.
4.2.0 introduces a soft budget. Each batch checks how much execution time remains via microtime() deltas against the configured limit, and stops before the kernel kills the request. Resumption happens naturally on the next page request: the plugin sees the partially-built cache, picks up the unprocessed entries, and continues. On a busy site that's serving traffic, the cache fills in gradually rather than catastrophically.
Cache invalidation on filename re-upload
If you replaced /images/articles/banner.jpg with a new version, previous versions of ochResponsiveImages saw the same filename and assumed the cached derivatives were still valid. The visible symptom: editors swore they'd updated the photo, but the site kept serving the old one until someone manually cleared the cache.
4.2.0 fingerprints the source file's modification time and file size, and compares that signature against what's stored alongside each cached derivative. When the signatures diverge, the derivatives are regenerated on demand. No manual cache-clear needed; the site Just Works.
Scheduled obsolete-file cleanup
Joomla's built-in task scheduler (introduced in Joomla 4) is how you run periodic background work without leaning on system cron. 4.2.0 ships with a new ochResponsiveImages task that you can schedule (daily, weekly, whatever) to walk the cache directory and delete derivatives whose source images no longer exist. On a long-running site that deletes and re-adds photos over the years, this prevents the cache folder from accumulating gigabytes of dead files.
Compatibility notes
4.2.0 requires Joomla 4.4+ or Joomla 5 (no Joomla 3 support — that branch has been frozen for a while). PHP 8.1+ for the new execution-time-aware code paths. The plugin uses GD or Imagick on the server to do the actual image conversion; most cPanel hosts (including ours) have both available.
Cybersalt's deployment plan
We'll wait for the production release on June 2nd, test on a couple of representative staging sites for a few days (one with heavy galleries, one with the existing setup), then roll out across the managed fleet during our normal weekly maintenance window. Clients with the gallery-optimization feature toggled on by request will be notified before the change goes live on their site.
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