Media library optimization — images smaller, sites faster
May 8, 2026. Native image optimization is now part of the Media Library. WebP conversion runs automatically. Responsive sizes are generated for every upload. Bulk re-encoding turns your existing library lighter without re-uploading.
What changed
Before: an image you uploaded shipped at the size you uploaded it. A 4 MB hero JPG stayed 4 MB on every page that referenced it. To shrink, you ran ImageOptim locally, re-uploaded, and updated every reference.
After: every upload runs through a server-side optimizer. WebP versions are generated automatically. Multiple responsive sizes are produced. The renderer picks the right size for the visitor's device. Your 4 MB JPG ships as a 280 KB WebP at appropriate dimensions per device — without you doing anything.
What runs automatically
On every Media Library upload:
- WebP conversion — modern browsers receive WebP (40-60% smaller than JPEG/PNG at the same visual quality). Older browsers fall back to the original.
- Responsive sizes — five variants generated per image: thumbnail (150px), small (480px), medium (768px), large (1280px), original. The HTML uses
+srcsetso each visitor downloads the right size for their viewport. - Lazy loading — images below the fold load only when scrolled into view. Reduces initial page weight.
- Aspect-ratio preservation — image elements get explicit width + height attributes so the page doesn't reflow as images load.
- Metadata strip — EXIF data is removed at upload (smaller files, no privacy leak from camera GPS).
Bulk re-encoding
For your existing Media Library (uploaded before May 8), bulk re-encoding turns existing assets into the optimized variants:
- Open Admin → Media → Optimization.
- Click Run Bulk Optimization.
- Pick a scope (all media, specific folders, specific date range).
- Click Start.
A 500-image library typically processes in 15-30 minutes. A 5,000-image library in 2-3 hours. The job runs at a polite rate to avoid impacting active site visitors.
Storage savings
After re-encoding, most libraries shrink by 40-60% in disk usage:
- JPG-heavy library — 50-60% reduction (WebP is the big win)
- PNG-heavy library — 30-50% reduction (PNG → WebP at quality 80 is usually invisible)
- GIF library — 20-30% reduction (animated GIFs convert to WebP-animated where supported)
Public-site impact
Sites that re-encode their library typically see:
- Page weight drops 30-50% on image-heavy pages
- Largest Contentful Paint (Core Web Vitals) drops 0.5-1.5 seconds
- Bandwidth costs (if you're on a metered plan) drop proportionally
- Mobile experience improves visibly — page renders earlier on slow connections
Why this matters
Image weight is the single biggest contributor to page speed for most marketing sites. Tooling exists to optimize manually (Squoosh, ImageOptim, TinyPNG) but it's per-image manual work and most operators don't do it consistently.
Bringing optimization native means it always runs. New uploads optimize on the way in. Existing libraries optimize via the bulk job. Page weight goes down without you remembering to run a script.
Common patterns
- Marketing site cleanup. Run bulk optimization once. Page weight drops, Core Web Vitals improve, you didn't have to touch any pages.
- Photography portfolio. Photographer uploads at 8-12 MB per image. Auto-optimization ships 400-800 KB to visitors. Image quality is preserved (visitors don't notice the difference); page speed transforms.
- Ecommerce product photos. Hundreds of product images at 2-4 MB each. After bulk re-encode, product pages load 2x faster on mobile. Conversion rate measurable improvement.
- Multi-tenant agency. Run bulk optimization across every client site. Each client gets faster pages without paying for the work.
What's not in this release
- Format choice per upload. Today the optimizer decides format (WebP for most cases, AVIF in NEXT for sites that opt in). Per-upload format control is in LATER.
- Lossless mode. Today's optimization is lossy (high quality, but lossy). Lossless mode for archives is in NEXT.
- Video optimization. This release is image-only. Video transcoding is its own roadmap item.
Behind the work
The April 14 changelog entry (media performance + storage efficiency) is the storage layer this builds on. The April 16 entry (media upload reliability + first-run setup) is the upload pipeline work — without it, the optimization queue wouldn't be reliable enough to ship to every account.
Next steps
- Read the Reference at Reference → Media Library → Optimization for the optimizer's full behavior.
- Run bulk optimization if your site is older than May 8 — typical sites see meaningful storage + page-speed wins from one job run.
- Check Site Vitals (in the SG-Dashboard) before and after the bulk job to quantify the speed improvement on your site.
