Skip to content
https://slack.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
93
GRADE
A
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from New York, United Stated
200 OK
Checks
9
6 PASS 2 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
TLS Certificate Expiry & Recommendations
89 days until leaf cert expires — 2 issues to address
REVIEW

Certificate validity

89
days left
0d 30d 60d 90d+

Recommended actions

  • Submit your domain to hstspreload.org to be added to the Chrome preload list
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
15 A records, 23 ms lookup
PASS
15 A records, 23 ms lookup
Info::
Resolves to 15 IPv4 address(es)
Got: 34.225.62.185, 34.193.255.5, 34.203.97.10, 34.204.109.226, 52.73.140.59, 54.92.199.186, 34.196.46.202, 54.225.153.205, 34.231.24.224, 3.210.88.6, 3.95.117.96, 54.147.59.169, 34.202.253.6, 54.163.235.119, 34.205.195.66
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-166.awsdns-20.com, ns-1493.awsdns-58.org, ns-606.awsdns-11.net, ns-1901.awsdns-45.co.uk
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::
SPF record present in TXT
Info::
DNS resolution time: 23 ms
Got: 23 ms
A34.225.62.185, 34.193.255.5, 34.203.97.10, 34.204.109.226, 52.73.140.59, 54.92.199.186, 34.196.46.202, 54.225.153.205, 34.231.24.224, 3.210.88.6, 3.95.117.96, 54.147.59.169, 34.202.253.6, 54.163.235.119, 34.205.195.66
AAAA—
CNAME—
NSns-166.awsdns-20.com, ns-1493.awsdns-58.org, ns-606.awsdns-11.net, ns-1901.awsdns-45.co.uk
MX
1 aspmx.l.google.com
5 alt2.aspmx.l.google.com
5 alt1.aspmx.l.google.com
10 aspmx3.googlemail.com
10 aspmx2.googlemail.com
TXT
google-site-verification=kB1KvgpSk9YkHsFmsj1VPI5YmDvfKctPxnplhGjyqtE
spycloud-domain-verification=02e4c0be-cf43-44e4-beaf-4f99702ca632
google-site-verification=2PK67oVPNyEtS1avSlr3PhH5nSiFuticbQv_bT4pM2k
hubspot-developer-verification=OTE4NzYxYTgtMDUwZi00MzgzLTk2YTUtZDAwNjBlODg1MWM0
SPF v=spf1 include:_spf.qualtrics.com include:mail.zendesk.com include:_spfextra.sla...
_0vidyxobp6x350odqhb4fo7fdxhmtq3
google-site-verification=v-LLB__IhraaI7ZzuE3jvRFIm2vERPLzWoepAEZJtKQ
google-site-verification=KqX3Ngw0XEjz_0GVx_xwFFlCoO-bskhqU_lxv0Q77mk
OSSRH-54733
google-site-verification=efuXt5-oMr2CdNmVi6A9IO29KMKifpseD1qokxjWwcE
google-site-verification=o2grd1TLmZZ8GrqbhVIFtzO2MRLTtSUpBBIBYfhQVCQ
google-site-verification=QvelFPjIOe3Vavw0q-aAVYaAPKmWCRjmmVVEAjgfjQc
CAALookup not available with standard resolver
Resolved in 23 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.

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

https://slack.com

149 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://slack.com200149 msHTTP/1.1Apache
A+
Crawlability
robots.txt present, sitemap with 13 URLs
PASS
robots.txt present, sitemap with 13 URLs
Info::
robots.txt is present
Got: 484 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 13 entries
Info::
Sitemap index with 13 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 484 B Sitemaps referenced 2 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /messages
Disallow: /quickstart
Disallow: /go/
Disallow: /unsub/
Disallow: /answers/
Disallow: /help/requests/new?app_id=*
Disallow: /what-is-slack
Disallow: /collaborating-with-slack
Disallow: /lp/three
Disallow: /documents/slack_pilot_dpa
Disallow: /openid
Disallow: /oauth
Disallow: /careers/
Disallow: /join/shared_invite
Disallow: /*?*
Disallow: /files-pri/

Sitemap: https://slack.com/sitemap.xml
Sitemap: https://slack.com/sitemaps/blog/news/sitemap.xml
sitemap.xml 200 OK
Type Sitemap Index URLs 13 entries Valid XML Yes
Child Sitemaps:
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

302https://www.slack.com/
200https://slack.com/

Preferred variant: non-www

HTTP → HTTPS

301http://slack.com/ → https://slack.com:443/

Consistent

A+
Domain Intelligence
slack.com — via MarkMonitor Inc., 33 years, 11 months old, hosted on AWS
PASS
slack.com — via MarkMonitor Inc., 33 years, 11 months old, hosted on AWS
Info::
Domain registered until Oct 20, 2027 (1 years, 6 months remaining)
Info::
DNSSEC is enabled
Info::
Registrar: MarkMonitor Inc.
Info::
Hosting: AWS
Got: AS16509
Domain expiry

491 days

October 20, 2027

SSL certificate

89 days

Issued by Let's Encrypt

Domain age

33 years, 11 months

Registered October 21, 1992

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

54.225.153.205

Registrar

MarkMonitor Inc.

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar MarkMonitor Inc.
Created October 21, 1992 (33 years, 11 months ago)
Expires October 20, 2027 (1 years, 6 months)
Last Updated September 18, 2025
Name Servers ns-1493.awsdns-58.org, ns-166.awsdns-20.com, ns-1901.awsdns-45.co.uk, ns-606.awsdns-11.net
DNSSEC Enabled
Hosting
IP Address 54.225.153.205
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.2s)
A+
HTTP Probe Timing
Total 153 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
2 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
7 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
8 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
153 ms
Total Time Total request time from DNS lookup through full response.
154 ms

Connection waterfall

DNS Lookup 2 ms TCP Connect 7 ms TLS Handshake 8 ms Server Processing 135 ms Content Transfer 1 ms
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback