Plan an image compression and optimization audit for a slow site
A scenario prompt for triaging a PageSpeed report into an image optimization plan, including the trap of third-party shortcode images that bulk optimizer plugins never touch.
Works with Claude / GPT340 uses★ 4
The prompt
media-image-compression-audit
Our homepage is failing Core Web Vitals. The PageSpeed Insights report flags two
specific issues: a 2.1MB hero image as the largest contentful paint element, and a
testimonial carousel that lazy-loads 8 uncompressed avatar images even though only
1 is visible at a time.
[paste your own PageSpeed/Lighthouse report summary here]
Build me an audit and fix plan, in priority order:
1. Which of these two issues to fix first, based on actual impact on LCP versus
total page weight, not just which one "sounds worse."
2. For the hero image: target format (WebP or AVIF), and whether it needs
fetchpriority=high instead of lazy-loading, since it's above the fold.
3. For the avatar carousel: whether all 8 need to load at full resolution at all,
given only one is visible at a time, versus loading the visible one at full
size and deferring the rest.
4. One thing a bulk "optimize all images" plugin run will miss: images embedded
via a third-party page builder shortcode or an iframe widget often live outside
the normal media library pipeline, so a plugin-wide bulk compression pass
silently skips them. Tell me how to find those on this specific page.
The instinct is to run a bulk optimizer plugin and call the audit done, but that only touches images registered in the media library through normal upload. Third-party widgets, shortcode galleries, and iframe-embedded images routinely sit outside that pipeline and keep serving full-size originals long after the “optimization” pass reports success.