HOW.IS
?

How is duolingo.com?

Looks fine risk 0/100

Registered 17 years ago, on no blocklists we checked, valid HTTPS, the site answered 200 in 78 ms.

Why

02050100
finecarefulhigh risk
  • ·Nothing in the checks added risk.

Rule-based: domain age, blocklists, TLS. A heuristic, not a guarantee.

How duolingo.com looks right now
The home page, rendered by how.is in a sandboxed browser. Nothing on it is clickable here.
Site
200
78 ms · ends at www.duolingo.com
HTTPS
196 d
left on a Amazon certificate
Age
17 years
registered 2010-01-26
Blocklists
0
listings across 5 lists

Everything we looked at

DNS records4 record types
A44.195.214.236
44.216.70.103
18.232.212.172
34.205.213.191
35.172.6.9
184.192.161.228
MX30 aspmx2.googlemail.com
20 alt1.aspmx.l.google.com
20 alt2.aspmx.l.google.com
30 aspmx3.googlemail.com
10 aspmx.l.google.com
30 aspmx5.googlemail.com
30 aspmx4.googlemail.com
NSns-247.awsdns-30.com
ns-1904.awsdns-46.co.uk
ns-1117.awsdns-11.org
ns-1020.awsdns-63.net
TXTopenai-domain-verification=dv-ieCpefZUqvVQwb8f7o4SlFye
stripe-verification=c8d270a115adc8c5a0a84fb24e17b7d05f66aad648d01e86f15548c6d0254ff5
openai-domain-verification=dv-A4cFxdrYIEodfG6UiQU0qxnT
jetbrains-domain-verification=bt8q7duih10l9pmf5fo5yy8wf
spacelift-domain-verification=519xtPXm
slack-domain-verification=iuNWYimCCkEpnistAJvWc4YOZF8izoZ23TCDek0I
v=spf1 ip4:100.25.59.11 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.8.0/21 ip4:52.73.203.75 ip4:52.70.130.33 include:amazonses.com include:_spf.google.com include:_spf.salesforce.com include:mail.zendesk.com include:aspmx.pardot.com ~all
h1-domain-verification=sjPBeaGqQwEe8YhJ3W8JVNJa7WDQFAzc6AHkURoErkh324Yy
klaviyo-site-verification=TGmZS7
_vg2bua41v8x489g1y55hg3hr4h3qmj0
e622flctk14s3cs3ccdauh8uth
docker-verification=b4ead4c5-fd66-42a5-a684-8f2e7f4c1417
anthropic-domain-verification-z4335b=YssTBALPY7K784Sri4FjVHjd3
_unk4dr4wfi8ewll15dm34quued295mb
aliyun-site-verification=1acfc148-50be-45c8-a021-3c933fc8eff9
atlassian-sending-domain-verification=423a5faf-1cfa-4704-a38a-f7adae302dd6
pardot_208162_*=610bfb45f202232a79db94c298b30d14332a62a6894e695b025fa7949d7b03fa
google-site-verification=975UaH3lkKONB88HjWDDg34p8cdCqyTVSq_KGBAXrmU
rippling-domain-verification=9692f0635321f04d
amazonses:+SIz2NZPqYri3C+PSIyKShZIbuI4rNpbLlES7lmvpu4=
apple-domain-verification=bMPI889zOgALUenN
MS=ms66530579
klaviyo-site-verification=RKdcF3
pardot_208162_*=c15d5cb1b9f31e26058e1f30bda9e5d65c57cfeea37b34af8e1dd88474460e90
RegistrationAmazon Registrar, Inc.
registrarAmazon Registrar, Inc.
registered2010-01-26
expires2027-01-26
last changed2026-05-15
ownerc/o whoisproxy.com
nameserversns-1020.awsdns-63.net
ns-1117.awsdns-11.org
ns-1904.awsdns-46.co.uk
ns-247.awsdns-30.com
statusclient transfer prohibited
registered 2010-01-26expires 2027-01-26
HTTPS certificate196 days left
validyes
issuerAmazon
coversduolingo.com
protocolTLSv1.2
issued 2026-10-26expires 2027-05-11
DNSSECinsecure

Domain is not signed with DNSSEC

. → com → duolingo.com
Email authenticationexcellent
SPFpass v=spf1 ip4:100.25.59.11 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.8.0/21 ip4:52.73.203.75 ip4:52.70.130.33 include:amazonses.com include:_spf.google.com include:_spf.salesforce.com include:mail.zendesk.com include:aspmx.pardot.com ~all
DMARCpass policy reject
DKIMfound: google, k1, s1, s2

Whether mail claiming to be from this domain can be checked as genuine.

Security scoregrade B · 155/205
Basic Security
20/40missing: DNSSEC Enabled
Record Security
30/45missing: CAA Records, DKIM Presence
Advanced Security
20/25missing: IPv6 Support
Domain Reputation
50/50
Threat Detection
35/45missing: Fast-Flux Detection, Domain Age Check
Blocklists0 listings · 17 lookups
SURBL MultidomainURIBL MultidomainSpamCop44.195.214.236Barracuda44.195.214.236UCEPROTECT Level 144.195.214.236SpamCop35.172.6.9Barracuda35.172.6.9UCEPROTECT Level 135.172.6.9SpamCop18.232.212.172Barracuda18.232.212.172UCEPROTECT Level 118.232.212.172SpamCop184.192.161.228Barracuda184.192.161.228UCEPROTECT Level 1184.192.161.228SpamCop34.205.213.191Barracuda34.205.213.191UCEPROTECT Level 134.205.213.191

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=duolingo.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=duolingo.com"

MCP: add https://how.is/mcp to Claude, Codex or Cursor (one-line install) and ask for domain_trust on duolingo.com. Reference: /llms.txt.

Watch duolingo.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