T9 — Chapter 21 - E-commerce SEO

Criterion t9-images-produits-optimisees : Optimized product images — guide + checklist

PART 2 - Advanced Strategies Chapter 21 - E-commerce SEO Keyword : images produits optimisées

Here we are talking about a criterion that often makes the difference in auditing.

Criterion **T9 — Optimized product images** is part of our SEO checklist (335 criteria).Here you have a **practical** method to check and correct it — with a concrete example.

What exactly this criterion covers

Here we are talking about a criterion that often makes the difference in auditing.

**T9 — Optimized product images** (Chapter 21 - E-commerce SEO): Multiple angles, zoom, descriptive alt text, WebP

Why it matters (SEO + UX)

Why it matters: it’s a lever for CTR and perception in SERP.When it is poorly applied, we often observe: ambiguity (bad associated query), duplication between pages, or loss of performance on loading times.

On sites generated in volume, this criterion also serves as a **safeguard**: a stable rule avoids 1,000 errors at once.

How to check (step by step)

Approach: tooled test (validator / performance).Recommended tool: **Screaming Frog (images)**.

  1. Open the page in Chrome → DevTools → Performance/Network tab.
  2. Run Lighthouse and note the main weak point.
  3. Check if the problem repeats on money pages.

Tip: first isolate 10 “representative” URLs (top pages + generated pages) before scaling the correction.

How to correct properly

Strategy: correct the minimum necessary, then stabilize.

  • Converted to WebP/AVIF + compress (Squoosh/ImageOptim).
  • Add width/height to avoid CLS.
  • Write a contextual alt (useful, not stuffed with keywords).

Next: re-crawl 50–200 URLs, then monitor Search Console over 7–14 days (impressions/CTR/indexing).

Concrete example (illustrative)

Example (illustrative):

  • **Context**: product sheet for dentist in Nice
  • **Before**: Images in PNG 2–4 MB, no explicit dimensions.
  • **After**: WebP/AVIF conversion + dimensions + descriptive alt (context: product sheet).
  • **Note**: Objective: reduce weight and improve rendering (and sometimes image search).

Checklist to tick

  • [ ] Optimized weight
  • [ ] Respects: webp
  • [ ] Modern format
  • [ ] Defined dimensions
  • [ ] Useful and contextual Alt
FAQ

Frequently asked questions — T9

What is the most common error on “Optimized product images”?

Applying an automatic pattern that is too generic (same logic on all pages) without adding a differentiating element.

Which tool is the fastest to control at scale?

For this type of criteria, a crawl (e.g. Screaming Frog) + a targeted check in Screaming Frog (images) is generally the fastest combo.

How to prevent this from happening again on 10K pages generated?

Freeze an auto-generation rule (title/structure/schema/URLs) + add an automatic check (crawl or test) before import into production.

Ready to go from theory to action?

Validate this criterion with an audit, then deepen the method in the Academy.

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