Website readiness profile · Snapshot 23 October 2026
costcotravel.com
costcotravel.com's public homepage, certificate and DNS checked against 31 practices and compared with 478 Travel Bookings & Trip Planning sites.
- Readiness index
- 56/100
- Ahead of
- 16%
- Practices observed
- 15/31
- Popularity band
- Top 10K
Travel Bookings & Trip Planning median 68
of measured Travel Bookings & Trip Planning sites
0 of 31 could not be measured
Chrome UX Report top-sites list
Readiness by lane
Green: costcotravel.com. Thin bar: Travel Bookings & Trip Planning peer median.
Enable
56/100
Peers 86
Harden
69/100
Peers 60
Accelerate
38/100
Peers 64
Recover
0/100
Peers 13
Priority fixes for costcotravel.com
Ordered by impact and by how common each practice is among peers.
Priority 1 · Harden
TLS 1.3 negotiated
Observed: The TLS connection negotiated TLSv1.2.
Why it matters: TLS 1.3 removes legacy cipher suites and completes the handshake in fewer round trips, so it is both safer and faster for new connections.
What to do: Enable TLS 1.3 on your CDN or server. Keep TLS 1.2 available for older clients unless you have checked your audience.
92% of Travel Bookings & Trip Planning peers do this. Limit: Certificate and protocol were observed from one vantage point; CDNs can present different certificates by region.
Priority 2 · Enable
XML sitemap discoverable
Observed: No sitemap was listed in robots.txt or found at /sitemap.xml.
What to do: Generate an XML sitemap of canonical URLs, reference it in robots.txt and submit it in Google Search Console.
83% of Travel Bookings & Trip Planning peers do this.
Guide: XML Sitemap Guide: Include Only URLs You Stand Behind
Priority 3 · Accelerate
Static files cached for 30 days or more
Observed: A same-site stylesheet or script was cacheable for 1 days, short of the 30-day benchmark.
What to do: Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.
49% of Travel Bookings & Trip Planning peers do this.
Priority 4 · Accelerate
Modern image formats in use
Observed: The homepage had 67 images and none used WebP or AVIF.
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.
41% of Travel Bookings & Trip Planning peers do this.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
What costcotravel.com already does well
Practices fewer than half of Travel Bookings & Trip Planning peers use.
- Content Security Policy presentContent-Security-Policy present.30% of peers
- Referrer-Policy setReferrer-Policy present.32% of peers
- HSTS kept for at least a yearHSTS with a 365-day max-age covering subdomains.46% of peers
What we saw
- Homepage checked
- https://www.costcotravel.com/
- Homepage response
- HTTP 200
- TLS
- TLSv1.2, HTTP/2
- Certificate
- DigiCert, 198-day validity, expiring 2027-03-19
- CDN or edge
- Akamai
- DNS operators
- Akamai Edge DNS
- HSTS
- max-age 365 days, includeSubDomains
- DMARC policy
- p=reject
- Homepage HTML
- 355 KB, gzip
- Images on homepage
- 67 (svg 55, png 5, gif 4, jpg 2)
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 16
- TLS 1.3 negotiated
- Certificate lifetime of 100 days or less
- CAA records limit who can issue certificates
- DNSSEC signed
- security.txt published
- HTTP/3 advertised
- Static files cached for 30 days or more
- Modern image formats in use
- Offscreen images lazy-loaded
- No render-blocking scripts in <head>
- XML sitemap discoverable
- Reachable over IPv6
- Canonical URL declared
- Structured data present
- Social preview image set
- Nameservers spread across providers
Observed 15
- HTTP requests move to HTTPS
- HSTS kept for at least a year
- Certificate has more than 14 days left
- DMARC policy enforces quarantine or reject
- X-Content-Type-Options: nosniff
- Framing restricted
- Content Security Policy present
- Referrer-Policy set
- HTTP/2 negotiated
- HTML compressed
- robots.txt published
- Meta description written
- Mobile viewport configured
- Page language declared
- At most one redirect to the homepage
Own costcotravel.com?
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: costcotravel.com. This profile covers configuration only.