E4 — Chapter 5 - URL

Criterion E4: URLs in lowercase — guide + checklist

PART 1 - Fundamentals Chapter 5 - URL Keyword : urls en minuscules

This is a criterion that often makes a difference in audits.

Criterion E4 — URLs in lowercase is part of our SEO checklist (335 criteria). Here, you have a practical method to check and fix it — with a concrete example.

What exactly this criterion covers

This is a criterion that often makes a difference in audits.

E4 — URLs in lowercase (Chapter 5 - URL): All lowercase, avoid uppercase (case sensitive)

Why it matters (SEO + UX)

Why it matters: it is a UX point that eventually translates into SEO. When poorly applied, common issues include ambiguity (wrong associated query), duplication between pages, or loss of performance on indexing rate.

On high-volume generated sites, this criterion also acts as a safeguard: a stable rule prevents 1,000 errors at once.

How to check (step by step)

Approach: tool-assisted test (validator / performance). Recommended tool: Search Console (Coverage).

  1. Crawl (Screaming Frog): 200/301/404 + canonicals + depth.
  2. Check the anchor and target page (intent consistency).
  3. Verify stability (no unnecessary parameters, no redirect chains).

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

How to fix properly

Strategy: fix + add a safeguard for mass import.

  • Define a stable URL rule (readable slug, no ID/parameters).
  • Implement canonical/301 if you change URLs.
  • Avoid redirect chains and check the sitemap.

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

Concrete example (illustrative)

Example (illustrative):

  • Context: FAQ page for insurance in Nice
  • Before: /service?id=123&city=nice (poorly readable URL)
  • After: /insurance/nice/urls-in-lowercase (clean URL)
  • Note: Goal: stable, understandable URL without duplication.

Checklist to tick

  • [ ] Readable
  • [ ] All lowercase
  • [ ] Stable
  • [ ] Consistent canonical/301
  • [ ] No unnecessary parameters
FAQ

Frequently asked questions — E4

What is the most common mistake on “URLs in lowercase”?

Trying to “optimize” by adding too many keywords, which degrades readability and creates repetitions.

Which tool is the fastest for large-scale checking?

For this type of criterion, a crawl (e.g. Screaming Frog) plus targeted verification in Search Console (Coverage) is generally the fastest combo.

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

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

Ready to go from theory to action?

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