How is stackoverflow.com?
Looks fine
risk 0/100
Registered 23 years ago, on no blocklists we checked, valid HTTPS, the site answered 403 in 106 ms.
Why
02050100
finecarefulhigh risk
- ·Nothing in the checks added risk.
Rule-based: domain age, blocklists, TLS. A heuristic, not a guarantee.
The home page, rendered by how.is in a sandboxed browser. Nothing on it is clickable here.
Site
403
106 ms
HTTPS
76 d
left on a Let's Encrypt certificate
Age
23 years
registered 2003-12-26
Blocklists
0
listings across 5 lists
Everything we looked at
DNS records5 record types
| A | 198.252.206.1 |
|---|---|
| MX | 10 alt3.aspmx.l.google.com 10 alt4.aspmx.l.google.com 5 alt1.aspmx.l.google.com 5 alt2.aspmx.l.google.com 1 aspmx.l.google.com |
| NS | damian.ns.cloudflare.com sureena.ns.cloudflare.com |
| TXT | cursor-domain-verification-sb0ayf=Pk6AyptQuTpzpcuSlfYGWloxv ZOOM_verify_AbkNwz5bBl0eurcDKyhhuk google-site-verification=ctogLnZNAdc_CXq8yOhODMLpmugGynjxKecKHDz4oL8 onetrust-domain-verification=0d9d67f856334905a54256085a5768b3 profound-domain-verification-5p599x=hWudYd2Du6WOYOod5ko9Rwnp8 google-site-verification=2Bi6SYw5skkRexdtdLPL2gpxeIhLxnYVqITVP9Htl3w onetrust-domain-verification=e445562296a64c649ae3d520230b8c4c work-os-domain-verification-43a3e0=GoDUTSc5MMjDaiIC3s5yRKqMD make-domain-verification=eec31159-f381-4f38-9d89-e59123dd023e google-site-verification=o3EMam8yBGo1yEjyybIiZcOunGHOQKpo8JmOtp9n1BU docker-verification=d65aee54-9091-4ceb-b792-61f5d5804050 docusign=4262531d-29f4-4a62-9f33-ae9f66f5247b adobe-idp-site-verification=25ba5203f3687c9cd6ee3223ee5de1528917828d1da3ebd3bd9a44094cbfc4ac google-site-verification=rdWtMbplKjbRHGr2dNONfwkqithlUvjr3u6i8QEz_mo MS=ms52592611 ibmid=4e7cbbb3-5f12-40b4-96c7-5b064347b822 openai-domain-verification=dv-GLNufzbWDzAq0fDXHD6jxeCK anthropic-domain-verification-q70207=cKyy0llXkD10O4rDQpWz8tQ5K v=spf1 ip4:52.38.191.241 include:_spf.google.com include:mailgun.org include:sendgrid.net include:mail.zendesk.com include:spf.tipalti.com ~all v=MCPv1; k=ed25519; p=VhBofO8RaYvTvHT7q5tTty+HQeCU8R6h5Y8k/sj20So= atlassian-domain-verification=byLeZgl3MIcfOqwWuMhq8Fhr/1zem/jIaouJegvDZbBKUU5OqhwDjdpkyYg5CTzm apple-domain-verification=O9jlnJXAQ7sNSZqC |
| CAA | {'type': 'CAA', 'issue': 'pki.goog; cansignhttpexchanges=yes', 'critical': 0} {'type': 'CAA', 'critical': 0, 'issuewild': 'letsencrypt.org'} {'type': 'CAA', 'critical': 0, 'issuewild': 'comodoca.com'} {'type': 'CAA', 'critical': 0, 'issuewild': 'ssl.com'} {'type': 'CAA', 'issue': 'digicert.com; cansignhttpexchanges=yes', 'critical': 0} {'type': 'CAA', 'issue': 'ssl.com', 'critical': 0} {'type': 'CAA', 'critical': 0, 'issuewild': 'sectigo.com'} {'type': 'CAA', 'issue': 'sectigo.com', 'critical': 0} {'type': 'CAA', 'critical': 0, 'issuewild': 'pki.goog; cansignhttpexchanges=yes'} {'type': 'CAA', 'issue': 'comodoca.com', 'critical': 0} {'type': 'CAA', 'iodef': 'mailto:sysadmin-team@stackoverflow.com', 'critical': 128} {'type': 'CAA', 'critical': 0, 'issuewild': 'digicert.com; cansignhttpexchanges=yes'} {'type': 'CAA', 'issue': 'letsencrypt.org', 'critical': 0} |
RegistrationCSC Corporate Domains, Inc.
| registrar | CSC Corporate Domains, Inc. |
|---|---|
| registered | 2003-12-26 |
| expires | 2027-02-02 |
| last changed | 2026-01-29 |
| owner | Stack Exchange, Inc. |
| nameservers | damian.ns.cloudflare.com sureena.ns.cloudflare.com |
| status | client transfer prohibited |
registered 2003-12-26expires 2027-02-02
HTTPS certificate76 days left
| valid | yes |
|---|---|
| issuer | Let's Encrypt |
| covers | *.stackoverflow.com, stackoverflow.com |
| protocol | TLSv1.3 |
issued 2026-10-13expires 2027-01-11
DNSSECinsecure
Domain is not signed with DNSSEC
. → com → stackoverflow.com
Email authenticationexcellent
| SPF | pass v=spf1 ip4:52.38.191.241 include:_spf.google.com include:mailgun.org include:sendgrid.net include:mail.zendesk.com include:spf.tipalti.com ~all |
|---|---|
| DMARC | pass policy reject |
| DKIM | found: google, k1, s1, s2 |
Whether mail claiming to be from this domain can be checked as genuine.
Security scoregrade B · 170/205
Basic Security10/40missing: DNSSEC Enabled, Nameserver Diversity
Record Security45/45missing: DKIM Presence
Advanced Security20/25missing: IPv6 Support
Domain Reputation50/50
Threat Detection45/45missing: Domain Age Check
Blocklists0 listings · 5 lookups
SURBL MultidomainURIBL MultidomainSpamCop198.252.206.1Barracuda198.252.206.1UCEPROTECT Level 1198.252.206.1
Green: clean. Red: listed. Grey: the list did not answer.
Ask it yourself
Agents get this as data. Bought through the API, the checks behind this page cost $0.070: profile $0.025 + trust $0.020 + screenshot $0.020 + site status $0.005.
curl "https://how.is/v1/domain/trust?domain=stackoverflow.com" \
-H "Authorization: Bearer $HOWIS_KEY"
# or pay per call in USDC (x402), no key: the 402 tells your agent the price
curl -i "https://how.is/v1/domain/profile?domain=stackoverflow.com"
MCP: add https://how.is/mcp to Claude, Codex or Cursor
(one-line install) and ask for domain_trust on stackoverflow.com.
Reference: /llms.txt.
Watch stackoverflow.com. DNS read at the source every 5 minutes; certificate, blocklists and expiry every 6 hours. You get an email only when something changes.
Watch — $1 / 30 days