How is grammarly.io?

Be careful risk 20/100

Registered 12 years ago, no valid HTTPS certificate, the site did not answer (OSError).

Why

02050100

finecarefulhigh risk

+20No valid HTTPS certificate.

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

Site

down

OSError

HTTPS

invalid

Could not resolve host (ENODATA)

Age

12 years

registered 2015-02-10

Blocklists

listings across 2 lists

Everything we looked at

DNS records3 record types

MX	10 aspmx2.googlemail.com 5 alt2.aspmx.l.google.com 1 aspmx.l.google.com 10 aspmx3.googlemail.com 5 alt1.aspmx.l.google.com
NS	ns-1862.awsdns-40.co.uk ns-1503.awsdns-59.org ns-665.awsdns-19.net ns-112.awsdns-14.com
TXT	anthropic-domain-verification-s28h6q=v2jDy3xfB0txQbkdDByVhXhRr google-site-verification=ztwrhPcHMBkLdHiC0p4WYJHW5DQqOB8G4u7w2rS8mGc v=spf1 include:_spf.google.com ~all

RegistrationMarkMonitor Inc.

registrar	MarkMonitor Inc.
registered	2015-02-10
expires	2030-02-10
last changed	2026-08-11
owner	Grammarly, Inc.
nameservers	ns-665.awsdns-19.net ns-1862.awsdns-40.co.uk ns-1503.awsdns-59.org ns-112.awsdns-14.com
status	client delete prohibited client transfer prohibited client update prohibited

registered 2015-02-10expires 2030-02-10

HTTPS certificatenot valid

valid	no
problem	Could not resolve host (ENODATA)

DNSSECinsecure

Domain is not signed with DNSSEC

. → io → grammarly.io

Email authenticationexcellent

SPF	pass `v=spf1 include:_spf.google.com ~all`
DMARC	pass policy quarantine
DKIM	found: google

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

Security scoregrade B · 150/190

Basic Security

20/40missing: DNSSEC Enabled

Record Security

30/45missing: CAA Records, DKIM Presence

Advanced Security

20/25missing: IPv6 Support

Domain Reputation

35/35

Threat Detection

45/45missing: Domain Age Check

Blocklists0 listings · 2 lookups

SURBL MultidomainURIBL Multidomain

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=grammarly.io" \ -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=grammarly.io"

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

Watch grammarly.io. 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