You installed Smush (or ShortPixel, or Imagify), it compressed everything, and your site still loads slowly. A member hit exactly this on a recent WP AI Success Hub call, and the diagnosis surprised her — because compression plugins only fix half the image problem.

Compression reduces weight. It doesn't reduce size.

Optimisation plugins squeeze the file (fewer kilobytes per pixel) but keep the dimensions. If you upload a 4000-pixel-wide photo straight from your phone, Smush gives you a compressed 4000-pixel-wide photo — which the browser then squeezes into a 600-pixel column, throwing away most of what it downloaded.

The fix: resize before (or after) you upload

• Content images — resize to around 1000px wide before uploading. That covers nearly every blog and page layout at full quality.
• Logos and small graphics — they don't need more than ~500px; a 2000px logo is pure waste.
• Full-width hero images — the one exception; 1600–2000px is reasonable there.

Any free tool works for the resize — Preview on Mac, Photos on Windows, Squoosh in the browser. Some optimisation plugins can also auto-resize anything over a maximum width on upload; if yours has that setting, turn it on and set it to ~2000px as a safety net.

While you're at it: name the file properly

IMG_4382.jpg tells Google nothing. red-anti-aging-led-glove.jpg is an SEO signal, and so is the alt text you add in the Media Library. Rename before uploading — it takes five seconds and compounds across every image on your site.

Quick checklist

• Resize to the size the layout actually needs (~1000px for content)
• Descriptive, hyphenated filename before upload
• Alt text on every image
• Then let your compression plugin do its thing

Not sure what's slowing your site down?

Bring it to a live call — we run speed diagnostics on members' sites on screen and fix the biggest problem first, twice a week inside the WP AI Success Hub. Join for $27/month.