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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
82
GRADE
B
FIX
1
REVIEW
3
PASS
4
INFO
1
Probed from Madrid, Spain
200 OK
Checks
9
4 PASS 3 REVIEW 1 FIX
D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

B
Crawlability
robots.txt present, sitemap with 0 URLs
REVIEW
robots.txt present, sitemap with 0 URLs
Info::
robots.txt is present
Got: 870 bytes
Info::
sitemap.xml is present
Warning::
sitemap.xml contains invalid XML
Search engines may not be able to parse the sitemap. Fix XML validation errors.
Warning::
sitemap.xml is empty — no URLs found
An empty sitemap provides no value. Add <url> entries for your pages.
Info::
robots.txt references sitemap

Search engines may not be able to parse the sitemap. Fix XML validation errors.

Why this matters

An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.

Learn more ▾

Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.

Source: sitemaps.org / Google Search Central

An empty sitemap provides no value. Add <url> entries for your pages.

Why this matters

An empty sitemap signals 'no content to index' to Google — actively harmful versus having no sitemap at all.

Learn more ▾

Google compares URLs in the sitemap against URLs it has crawled. An empty sitemap on a site with thousands of pages signals abandonment. Either populate it correctly (most CMSes auto-generate) or delete the file and let Google crawl normally.

Source: Google Search Central / sitemaps.org

robots.txt 200 OK
Size 870 B Sitemaps referenced 1 User-agents *bot, *, Baiduspider, meta-externalagent, ClaudeBot, Yandex, Googlebot, AhrefsBot, anthropic-ai, openai, ChatGPT, bingbot Blocking No — crawling allowed

User-agent: *
Disallow: /api
Disallow: /edit
Disallow: /account
Disallow: /merges
Disallow: /search
Disallow: /search/publishers
Disallow: /search/authors
Disallow: /search/inside
Disallow: /search/subjects
Disallow: /search/lists
Disallow: /advancedsearch
Disallow: /publishers
Disallow: /books/add
Disallow: /qrcode
Disallow: */borrow*
Disallow: /*.rdf$

Sitemap: https://openlibrary.org/static/sitemaps/siteindex.xml.gz

User-agent: Baiduspider
Crawl-delay: 10

User-agent: Googlebot
Disallow: /*.rdf$
Crawl-delay: 10

User-agent: AhrefsBot
Crawl-delay: 10

User-agent: meta-externalagent
Crawl-delay: 10

User-agent: anthropic-ai
Crawl-delay: 10

User-agent: ClaudeBot
Crawl-delay: 10

User-agent: openai
Crawl-delay: 10

User-agent: ChatGPT
Crawl-delay: 10

User-agent: bingbot
Crawl-delay: 10

User-agent: Yandex
Crawl-delay: 10

User-agent: *bot
Crawl-delay: 10
sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
B
TLS Certificate Expiry & Recommendations
40 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

40
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A
DNS Records
1 A records, 161 ms lookup
PASS
1 A records, 161 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 207.241.234.205
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
3 nameserver(s) configured
Got: ns3.archive.org, ns1.archive.org, ns2.archive.org
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 161 ms
Got: 161 ms
A207.241.234.205
AAAA—
CNAME—
NSns3.archive.org, ns1.archive.org, ns2.archive.org
MX—
TXT
google-site-verification=vtXGm8q3UgP-f6qXTvQBo85uh3nmIYIotVqqdJDpyz4
84k4aufp68eh5qlo6bsfqmo7rm
C8VERH4US3NUDNOCBIDHLSO15
CAALookup not available with standard resolver
Resolved in 161 ms

Multiple A records provide failover if one server goes down.

Why this matters

Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.

Learn more ▾

Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.

Source: SRE practice / DNS architecture

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more ▾

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://openlibrary.org

https://openlibrary.org

1331 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://openlibrary.org2001331 msHTTP/1.1nginx/1.30.0
A
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

301https://www.openlibrary.org/
200https://openlibrary.org/

Preferred variant: non-www

HTTP → HTTPS

302http://openlibrary.org/ → https://openlibrary.org/

Use 301 (permanent) instead of 302 (temporary)

A
HTTP Probe Timing
Total 785 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
22 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
157 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
264 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
785 ms
Total Time Total request time from DNS lookup through full response.
786 ms

Connection waterfall

DNS Lookup 22 ms TCP Connect 157 ms TLS Handshake 264 ms Server Processing 342 ms Content Transfer 1 ms
Domain Intelligence
Domain intelligence data not available
INFO
Domain intelligence data not available

RDAP and WHOIS lookup both failed

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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