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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
78
GRADE
C
FIX
2
REVIEW
3
PASS
4
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
4 PASS 3 REVIEW 2 FIX
D
Redirect Chain
Action
3 redirect(s), 926 ms total
FIX
3 redirect(s), 926 ms total
Warning::
3 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
Redirect overhead: 926 ms total
Got: 926 ms
Info::
Cross-domain redirect detected

https://atom.io

294 ms · HTTP/1.1

301

https://github.blog/2022-06-08-sunsettin...

280 ms · HTTP/1.1

301

https://github.blog/engineering/sunsetti...

347 ms · HTTP/1.1

301

https://github.blog/news-insights/produc...

6 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://atom.io301294 msHTTP/1.1
2https://github.blog/2022-06-08-sunsettin...301280 msHTTP/1.1nginx
3https://github.blog/engineering/sunsetti...301347 msHTTP/1.1nginx
4https://github.blog/news-insights/produc...2006 msHTTP/1.1nginx

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

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

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-US" class="mt-0">
<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<link rel="profile" href="https://gmpg.org/xfn/11">
	<link rel="icon" type="image/x-icon" href="https://github.githubassets.com/favicon.ico">
	<meta name='robots' content='noindex, follow' />

	<!-- This site is optimized with the Yoast SEO Premium plugin v27.3 (Yoast SEO v27.3) - https://yoast.com/product/yoast-seo-premium-wordpress/ -->
	<title>Sunsetting Atom - The GitHub Blog</title>
	<meta name="description" content="We are archiving Atom and all projects under the Atom organization for an official sunset on December 15, 2022." />
	<meta property="og:locale" content="en_US" />
	<meta property="og:type" content="article" />
	<meta property="og:title" content="Sunsetting Atom" />
	<meta property="og:description" content="We are archiving Atom and all projects under the Atom organization for an official sunset on December 15, 2022." />
	<meta property="og:url" content="https://github.blog/news-insights/product-news/sunsetting-atom/" />
	<meta property="og:site_name" content="The GitHub Blog" />
	<meta property="article:published_time" content="2022-06-08T15:00:23+00:00" />
	<meta property="article:modified_time" content="2024-07-23T15:28:33+00:00" />
	<meta property="og:image" content="https://github.blog/wp-content/uploads/2022/06/Engineering-Product@2x.png" />
	<meta property="og:image:width" content="2400" />
	<meta property="og:image:height" content="1260" />
	<meta property="og:image:type" content="image/png" />
	<meta name="author" content="GitHub Staff" />
	<meta name="twitter:card" content="summary_large_image" />
	<meta name="twitter:label1" content="Written by" />
	<meta name="twitter:data1" content="GitHub Staff" />
	<meta name="twitter:label2" content="Est. reading time" />
	<meta name="twitter:data2" content="3 minutes" />
<script type='application/ld+json'>{"@context":"https:\/\/schema.org","headline":"Sunsetting Atom","author":{"@type":"Person","name":"GitHub Staff"},"datePublished":"2022-06-08T08:00:23-07:00","abstract":"We are archiving Atom and all projects under the Atom organization for an official sunset on December 15, 2022.","mainEntityOfPage":{"@type":"WebPage","@id":"https:\/\/github.blog\/news-insights\/product-news\/sunsetting-atom\/"},"image":"https:\/\/github.blog\/wp-content\/uploads\/2022\/06\/Engineering-Product@2x.png?resize=150%2C150","@type":"TechArticle"}</script>
<script type='application/ld+json'>{"@context":"https:\/\/schema.org","headline":"Sunsetting Atom","author":{"@type":"Person","name":"GitHub Staff"},"datePublished":"2022-06-08T08:00:23-07:00","abstract":"We are archiving Atom and all projects under the Atom organization for an official sunset on December 15, 2022.","mainEntityOfPage":{"@type":"WebPage","@id":"https:\/\/github.blog\/news-insights\/product-news\/sunsetting-atom\/"},"image":"https:\/\/github.blog\/wp-content\/uploads\/2022\/06\/Engineering-Product@2x.png?resize=150%2C150","@type":"BlogPosting"}</script>
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sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
B
TLS Certificate Expiry & Recommendations
69 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

69
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, 45 ms lookup
PASS
1 A records, 45 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 140.82.114.17
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: dns3.p02.nsone.net, dns4.p02.nsone.net, dns2.p02.nsone.net, dns1.p02.nsone.net
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::
SPF record present in TXT
Info::
DNS resolution time: 45 ms
Got: 45 ms
A140.82.114.17
AAAA—
CNAME—
NSdns3.p02.nsone.net, dns4.p02.nsone.net, dns2.p02.nsone.net, dns1.p02.nsone.net
MX—
TXT
SPF v=spf1 include:mailgun.org ~all
CAALookup not available with standard resolver
Resolved in 45 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.

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)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

301https://www.atom.io/
200https://atom.io/

Preferred variant: non-www

HTTP → HTTPS

301http://atom.io/ → https://github.blog/2022-06-08-sunsetting-atom/

Consistent

A+
Domain Intelligence
atom.io — via MarkMonitor Inc., 16 years, 6 months old, hosted on GitHub Pages
PASS
atom.io — via MarkMonitor Inc., 16 years, 6 months old, hosted on GitHub Pages
Info::
Domain registered until Jan 6, 2027 (8 months remaining)
Info::
Registrar: MarkMonitor Inc.
Info::
Registrar lock is enabled
Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.
Info::
Hosting: GitHub Pages
Got: AS36459
Domain expiry

205 days

January 6, 2027

SSL certificate

69 days

Issued by Sectigo Limited

Domain age

16 years, 6 months

Registered January 6, 2010

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

GitHub Pages

ASN AS36459

140.82.114.17

Registrar

MarkMonitor Inc.

Locked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar MarkMonitor Inc.
Created January 6, 2010 (16 years, 6 months ago)
Expires January 6, 2027 (8 months)
Last Updated December 10, 2024
Name Servers dns4.p02.nsone.net, dns3.p02.nsone.net, dns2.p02.nsone.net, dns1.p02.nsone.net
Registrant GitHub, Inc.
Hosting
IP Address 140.82.114.17
ASN AS36459 (GITHUB - GitHub, Inc., US)
Provider GitHub Pages
Data source: whois (1.6s)

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 330 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
37 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
95 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
103 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
330 ms
Total Time Total request time from DNS lookup through full response.
330 ms

Connection waterfall

DNS Lookup 37 ms TCP Connect 95 ms TLS Handshake 103 ms Server Processing 96 ms Content Transfer 0 ms
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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