Category benchmark · Snapshot 23 October 2026

Airlines: website readiness

31 configuration checks across 91 Airlines sites from the SID website catalog, with 60 individual profiles for sites in the Chrome UX Report top 50K.

Sites measured: 91
Median readiness index: 63/100
Profiles: 60
Weakest lane: Recover

Readiness by lane

Enable

74/100

All sites 77

Harden

60/100

All sites 56

Accelerate

56/100

All sites 64

Recover

19/100

All sites 10

Biggest gaps for Airlines sites

The checks with the most room to improve, weighted by impact.

Modern image formats in use
31% observed · all sites 40%
Serve WebP or AVIF with a JPEG or PNG fallback, either through an image CDN or by generating both formats at build time.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
security.txt published
9.3% observed · all sites 7.1%
Publish /.well-known/security.txt with at least Contact and Expires fields, as RFC 9116 requires, and review it before it expires.
Guide: A Practical Website Health Check for Owners
CAA records limit who can issue certificates
9.9% observed · all sites 13%
Publish CAA records naming every CA you actually use, including the CAs your CDN uses for managed certificates. Add an iodef contact if you want reports.
Guide: HTTPS and TLS Guide for Website Owners
Static files cached for 30 days or more
40% observed · all sites 51%
Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.
Guide: Browser Caching Guide for Website Owners
HTTP/3 advertised
16% observed · all sites 37%
Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.
Guide: CDN Guide for Website Owners
HSTS kept for at least a year
60% observed · all sites 34%
Send Strict-Transport-Security on HTTPS responses. Start with a short max-age (for example 300 seconds), confirm every subdomain works over HTTPS, then raise it in steps to 31536000. Add includeSubDomains only when all subdomains are HTTPS. HSTS preload is optional and hard to undo; hstspreload.org itself does not recommend it by default.
Guide: HTTPS and TLS Guide for Website Owners

Where Airlines sites lead

HSTS kept for at least a year60% observedall sites 34%
DMARC policy enforces quarantine or reject63% observedall sites 39%
Framing restricted60% observedall sites 51%
robots.txt published85% observedall sites 76%

Stack mix

CDN and edge

Platform or framework

DNS operator

Certificate authority

DigiCert23%
Let's Encrypt20%
Google Trust Services18%
Sectigo11%
Amazon8.8%
GlobalSign6.6%
Entrust Limited3.3%
GoDaddy2.2%

Readiness leaders

Airlines sites in the top 50K with the highest share of observed practices (at least 26 of 31 checks measured). This lists only what we observed on 23 October 2026; owners can request a correction.

All 31 checks for Airlines

Check	Lane	Observed	All sites	Measured
HTTP requests move to HTTPS	Harden	87%	91%	83
HSTS kept for at least a year	Harden	60%	34%	91
TLS 1.3 negotiated	Harden	91%	91%	89
Certificate has more than 14 days left	Harden	99%	99%	89
Certificate lifetime of 100 days or less	Harden	39%	67%	89
CAA records limit who can issue certificates	Harden	9.9%	13%	91
DNSSEC signed	Harden	7.7%	8%	91
security.txt published	Harden	9.3%	7.1%	86
DMARC policy enforces quarantine or reject	Harden	63%	39%	91
X-Content-Type-Options: nosniff	Harden	56%	48%	91
Framing restricted	Harden	60%	51%	91
Content Security Policy present	Harden	32%	32%	91
Referrer-Policy set	Harden	25%	24%	91
HTTP/2 negotiated	Accelerate	85%	90%	89
HTTP/3 advertised	Accelerate	16%	37%	91
HTML compressed	Accelerate	89%	93%	91
Static files cached for 30 days or more	Accelerate	40%	51%	77
Modern image formats in use	Accelerate	31%	40%	59
Offscreen images lazy-loaded	Accelerate	50%	62%	56
No render-blocking scripts in <head>	Accelerate	45%	48%	91
robots.txt published	Enable	85%	76%	89
XML sitemap discoverable	Enable	76%	70%	88
Reachable over IPv6	Enable	35%	48%	91
Canonical URL declared	Enable	60%	68%	91
Meta description written	Enable	84%	84%	91
Mobile viewport configured	Enable	97%	94%	91
Structured data present	Enable	30%	51%	91
Social preview image set	Enable	44%	57%	91
Page language declared	Enable	89%	90%	91
At most one redirect to the homepage	Enable	95%	98%	91
Nameservers spread across providers	Recover	19%	10%	90

Airlines profiles

Readiness index shown next to each site.

Airlines: website readiness

Readiness by lane

Biggest gaps for Airlines sites

Modern image formats in use

security.txt published

CAA records limit who can issue certificates

Static files cached for 30 days or more

HTTP/3 advertised

HSTS kept for at least a year