Website readiness profile · Snapshot 23 October 2026
openlibrary.org
openlibrary.org's public homepage, certificate and DNS checked against 31 practices and compared with 696 Literary & Knowledge sites.
- Readiness index
- 62/100
- Ahead of
- 48%
- Practices observed
- 17/31
- Popularity band
- Top 50K
Literary & Knowledge median 62
of measured Literary & Knowledge sites
0 of 31 could not be measured
Chrome UX Report top-sites list
Readiness by lane
Green: openlibrary.org. Thin bar: Literary & Knowledge peer median.
Enable
79/100
Peers 78
Harden
46/100
Peers 51
Accelerate
75/100
Peers 62
Recover
0/100
Peers 6
Priority fixes for openlibrary.org
Ordered by impact and by how common each practice is among peers.
Priority 1 · Harden
HSTS kept for at least a year
Observed: The homepage response did not include a Strict-Transport-Security header.
Why it matters: HSTS tells browsers to use HTTPS for your host on every later visit, which removes the window where a first HTTP request can be intercepted.
What to do: 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.
28% of Literary & Knowledge peers do this. Limit: Read from the homepage response only; other pages or regions may send different headers.
Priority 2 · Accelerate
Modern image formats in use
Observed: The homepage had 49 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.
31% of Literary & Knowledge peers do this.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
Priority 3 · Harden
DMARC policy enforces quarantine or reject
Observed: No DMARC record was found at _dmarc.openlibrary.org.
What to do: Publish DMARC with p=none and a reporting address first, fix any legitimate senders that fail SPF or DKIM alignment, then move to quarantine and finally reject.
22% of Literary & Knowledge peers do this.
Priority 4 · Accelerate
HTTP/3 advertised
Observed: The homepage did not advertise HTTP/3 through an Alt-Svc header.
What to do: Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.
47% of Literary & Knowledge peers do this.
What openlibrary.org already does well
Practices fewer than half of Literary & Knowledge peers use.
- Referrer-Policy setReferrer-Policy present.22% of peers
- No render-blocking scripts in <head>Head scripts load without blocking.48% of peers
- Offscreen images lazy-loadedNative lazy loading in use.48% of peers
What we saw
- Homepage checked
- https://openlibrary.org/
- Homepage response
- HTTP 200
- TLS
- TLSv1.3, HTTP/2
- Certificate
- Let's Encrypt, 89-day validity, expiring 2026-11-27
- DNS operators
- 1 self-run or other nameserver domain
- Homepage HTML
- 91 KB, gzip
- Images on homepage
- 49 (jpg 36, png 7, svg 6)
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 14
- HSTS kept for at least a year
- CAA records limit who can issue certificates
- DNSSEC signed
- security.txt published
- DMARC policy enforces quarantine or reject
- X-Content-Type-Options: nosniff
- Framing restricted
- Content Security Policy present
- HTTP/3 advertised
- Modern image formats in use
- Reachable over IPv6
- Structured data present
- Social preview image set
- Nameservers spread across providers
Observed 17
- HTTP requests move to HTTPS
- TLS 1.3 negotiated
- Certificate has more than 14 days left
- Certificate lifetime of 100 days or less
- Referrer-Policy set
- HTTP/2 negotiated
- HTML compressed
- Static files cached for 30 days or more
- Offscreen images lazy-loaded
- No render-blocking scripts in <head>
- robots.txt published
- XML sitemap discoverable
- Canonical URL declared
- Meta description written
- Mobile viewport configured
- Page language declared
- At most one redirect to the homepage
Own openlibrary.org?
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: openlibrary.org. This profile covers configuration only.