Website readiness profile · Snapshot 23 October 2026
coolblue.be
coolblue.be's public homepage, certificate and DNS checked against 31 practices and compared with 5,718 E-Commerce & Marketplaces sites.
- Readiness index
- 78/100
- Ahead of
- 78%
- Practices observed
- 21/30
- Popularity band
- Top 50K
E-Commerce & Marketplaces median 71
of measured E-Commerce & Marketplaces sites
1 of 31 could not be measured
Chrome UX Report top-sites list
Readiness by lane
Green: coolblue.be. Thin bar: E-Commerce & Marketplaces peer median.
Enable
87/100
Peers 86
Harden
80/100
Peers 60
Accelerate
68/100
Peers 69
Recover
0/100
Peers 11
Priority fixes for coolblue.be
Ordered by impact and by how common each practice is among peers.
Priority 1 · Accelerate
Modern image formats in use
Observed: The homepage had 36 images and none used WebP or AVIF.
Why it matters: WebP and AVIF are typically much smaller than JPEG or PNG at similar quality, and images are often the heaviest part of a page.
What to do: Serve WebP or AVIF with a JPEG or PNG fallback, either through an image CDN or by generating both formats at build time.
On Next.js: The next/image component serves optimized formats automatically.
47% of E-Commerce & Marketplaces peers do this. Limit: Based on the homepage HTML delivered to an automated client; scripts that run later were not executed.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
Priority 2 · Accelerate
No render-blocking scripts in <head>
Observed: The homepage <head> loaded 1 external script without async or defer.
What to do: Add defer to scripts that need the DOM, async to independent ones such as analytics, or move them to the end of the body.
On Next.js: Use the next/script component with an appropriate loading strategy.
44% of E-Commerce & Marketplaces peers do this.
Guide: Control Third-Party Scripts Before They Control Your Page
Priority 3 · Harden
Certificate lifetime of 100 days or less
Observed: The certificate from Amazon had a 394-day validity period, longer than the 100-day maximum that applies from March 2027.
What to do: Move to automated issuance and renewal now, while you still have time to test it.
70% of E-Commerce & Marketplaces peers do this.
Priority 4 · Harden
X-Content-Type-Options: nosniff
Observed: The homepage response did not include X-Content-Type-Options: nosniff.
What to do: Send X-Content-Type-Options: nosniff on all responses and make sure each file is served with the correct Content-Type.
On Amazon CloudFront: Enable it in a response headers policy (security headers section).
64% of E-Commerce & Marketplaces peers do this.
What coolblue.be already does well
Practices fewer than half of E-Commerce & Marketplaces peers use.
- security.txt publishedsecurity.txt with a contact found.7.6% of peers
- Referrer-Policy setReferrer-Policy present.20% of peers
- HSTS kept for at least a yearHSTS with a 365-day max-age covering subdomains.32% of peers
What we saw
- Homepage checked
- https://www.coolblue.be/
- Homepage response
- HTTP 200, after 1 redirect
- TLS
- TLSv1.3, HTTP/2
- Certificate
- Amazon, 394-day validity, expiring 2027-02-17
- CDN or edge
- Amazon CloudFront
- Platform or framework
- Next.js
- DNS operators
- Amazon Route 53
- HSTS
- max-age 365 days, includeSubDomains, preload
- DMARC policy
- p=reject
- Homepage HTML
- 1,321 KB, gzip
- Images on homepage
- 36
Limits: homepage only, one location, one moment. Header checks reflect the homepage response; other pages may differ.
Stack and providers
Seen in the homepage response, certificate and DNS. Provider pages compare how their customers configure the same checks.
All 31 checks
Select a gap for the method and fix. How each check works
Not observed 9
Observed 21
- HTTP requests move to HTTPS
- HSTS kept for at least a year
- TLS 1.3 negotiated
- Certificate has more than 14 days left
- security.txt published
- DMARC policy enforces quarantine or reject
- Framing restricted
- Content Security Policy present
- Referrer-Policy set
- HTTP/2 negotiated
- HTTP/3 advertised
- HTML compressed
- Offscreen images lazy-loaded
- robots.txt published
- XML sitemap discoverable
- Canonical URL declared
- Meta description written
- Mobile viewport configured
- Structured data present
- Page language declared
- At most one redirect to the homepage
Not measured 1
- Static files cached for 30 days or more
Own coolblue.be?
Re-run the checks after a change, or verify the site in a free workspace to save reports with history, compare against similar sites and competitors, and track a private action plan. What owners get.
Live status for this site: Status Is Down: coolblue.be. This profile covers configuration only.