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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
83
GRADE
B
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Madrid, Spain
302 Found
Checks
9
6 PASS 2 REVIEW 1 FIX
D
Redirect Chain
Action
3 redirect(s), 739 ms total
FIX
3 redirect(s), 739 ms total
Warning::
3 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://readthedocs.io
Info::
Redirect overhead: 739 ms total
Got: 739 ms
Info::
Cross-domain redirect detected

https://readthedocs.io

88 ms · HTTP/1.1

302

https://readthedocs.org

89 ms · HTTP/1.1

302

https://app.readthedocs.org/welcome/

436 ms · HTTP/1.1

302

https://about.readthedocs.com/?ref=app.r...

125 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://readthedocs.io30288 msHTTP/1.1cloudflare
2https://readthedocs.org30289 msHTTP/1.1cloudflare
3https://app.readthedocs.org/welcome/302436 msHTTP/1.1cloudflare
4https://about.readthedocs.com/?ref=app.r...200125 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

Each redirect adds latency. Try to minimize the chain to 1 hop.

Why this matters

Redirect chain — each hop adds latency; combine into one redirect where possible.

Source: Google Search Central / web.dev

If permanent, use 301 instead.

Why this matters

302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.

Learn more ▾

Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).

Source: Google Search Central

C
Crawlability
Action
robots.txt present, sitemap with 0 URLs
REVIEW
robots.txt present, sitemap with 0 URLs
Info::
robots.txt is present
Got: 10240 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 does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your 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

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 10240 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Full featured documentation deployment platform - Read the Docs</title>
    <meta charset="utf-8" />
    <meta name="generator" content="Pelican" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <meta property="og:site_name" content="Read the Docs" />
    <meta property="og:type" content="article" />
    <meta property="og:title" content="Full featured documentation deployment platform" />
    <meta property="twitter:title" content="Full featured documentation deployment platform" />
    <meta name="description" content="Read the Docs is a documentation building and hosting platform aimed at helping developers creating documentation from code with versioned documentation, integrated search, pull request previews and more." />
    <meta property="og:description" content="Read the Docs is a documentation building and hosting platform aimed at helping developers creating documentation from code with versioned documentation, integrated search, pull request previews and more." />
    <meta property="twitter:description" content="Read the Docs is a documentation building and hosting platform aimed at helping developers creating documentation from code with versioned documentation, integrated search, pull request previews and more." />
    <meta property="og:image" content="/images/logo-opengraph.png" />
    <meta property="twitter:image" content="/images/logo-opengraph.png" />
    <meta name="author" content="Read the Docs, Inc" />


    <link rel="apple-touch-icon" sizes="180x180" href="https://about.readthedocs.com/theme/img/apple-touch-icon.png">
    <link rel="icon" type="image/png" sizes="32x32" href="https://about.readthedocs.com/theme/img/favicon-32x32.png">
    <link rel="icon" type="image/png" sizes="24x24" href="https://about.readthedocs.com/theme/img/favicon-24x24.png">
    <link rel="icon" type="image/png" sizes="16x16" href="https://about.readthedocs.com/theme/img/favicon-16x16.png">
    <link rel="shortcut icon" href="https://about.readthedocs.com/theme/img/favicon.ico">

    <link href="https://about.readthedocs.com//feeds/atom.xml" type="application/atom+xml" rel="alternate" title="Read the Docs Atom Feed" />

    <link rel="stylesheet" type="text/css" href="https://about.readthedocs.com/theme/css/site.css" />
    <script src="https://kit.fontawesome.com/53af4251af.js" crossorigin="anonymous"></script>

    <script src="https://about.readthedocs.com/theme/js/vendor.js"></script>
    <script src="https://about.readthedocs.com/theme/js/site.js"></script>
<script async type="text/javascript" src="/_/static/javascript/readthedocs-addons.js"></script><meta name="readthedocs-project-slug" content="readthedocs-about" /><meta name="readthedocs-version-slug" content="latest" /><meta name="readthedocs-resolver-filename" content="/" /><meta name="readthedocs-http-status" content="200" /></head>

<body>



<div class="ui basic fitted attached segment">
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          <div class="ui horizontally fitted basic segment">
            <a href="https://about.readthedocs.com/" aria-label="Read the Docs homepage">
              <img class="ui image" src="https://about.readthedocs.com/theme/img/logo-wordmark-dark.svg" width="220" alt="Read the Docs logo"/>
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    Choosing a platform
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sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
B
TLS Certificate Expiry & Recommendations
68 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

68
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
2 A records, 31 ms lookup
PASS
2 A records, 31 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 104.16.253.120, 104.16.254.120
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2606:4700::6810:fd78, 2606:4700::6810:fe78
Info::
2 nameserver(s) configured
Got: ivan.ns.cloudflare.com, tegan.ns.cloudflare.com
Info::
5 mail exchanger(s) configured
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: 31 ms
Got: 31 ms
A104.16.253.120, 104.16.254.120
AAAA2606:4700::6810:fd78, 2606:4700::6810:fe78
CNAME—
NSivan.ns.cloudflare.com, tegan.ns.cloudflare.com
MX
1 aspmx.l.google.com
5 alt1.aspmx.l.google.com
5 alt2.aspmx.l.google.com
10 aspmx3.googlemail.com
10 aspmx2.googlemail.com
TXT—
CAALookup not available with standard resolver
Resolved in 31 ms

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+
IPv6 Readiness
IPv6 reachable (17 ms)
PASS
IPv6 reachable (17 ms)
Info::
IPv6 is configured and reachable at 2606:4700::6810:fd78, 2606:4700::6810:fe78
Got: 17 ms connect
IPv6 Ready
AAAA Records 2606:4700::6810:fd78, 2606:4700::6810:fe78 Connection Reachable (17 ms)
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

302https://www.readthedocs.io/
200https://readthedocs.io/

Preferred variant: non-www

HTTP → HTTPS

302http://readthedocs.io/ → https://readthedocs.org

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
readthedocs.io — via Cloudflare, Inc, 12 years old
PASS
readthedocs.io — via Cloudflare, Inc, 12 years old
Info::
Domain registered until Jun 14, 2028 (2 years, 2 months remaining)
Info::
Registrar: Cloudflare, Inc
Info::
Registrar lock is enabled
Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.
Domain expiry

703 days

June 14, 2028

SSL certificate

68 days

Issued by Google Trust Services

Domain age

12 years

Registered June 14, 2014

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2606:4700::6810:fe78

Registrar

Cloudflare, Inc

Locked 2 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar Cloudflare, Inc
Created June 14, 2014 (12 years ago)
Expires June 14, 2028 (2 years, 2 months)
Last Updated June 28, 2025
Name Servers ivan.ns.cloudflare.com, tegan.ns.cloudflare.com
Registrant DATA REDACTED
Hosting
IP Address 2606:4700::6810:fe78
Data source: whois (1.1s)

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Why this matters

Registrar lock (clientTransferProhibited et al.) prevents unauthorized domain transfers — strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A+
HTTP Probe Timing
Total 233 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
35 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
17 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
26 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
233 ms
Total Time Total request time from DNS lookup through full response.
233 ms

Connection waterfall

DNS Lookup 35 ms TCP Connect 17 ms TLS Handshake 26 ms Server Processing 156 ms Content Transfer 0 ms
A+
CDN & Delivery
Cloudflare (HIT)
PASS
Cloudflare (HIT)
Info::
Site is served via Cloudflare CDN (edge: CDG)
Got: cf-ray: 9efe91c5c8eb9efa-CDG
Info::
CDN cache status: HIT
CDN Detected: Cloudflare
Provider Cloudflare Cache Status HIT Evidence cf-ray: 9efe91c5c8eb9efa-CDG
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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