htmlvalidator.app

Get an email when its DNS, website or certificate changes.

htmlvalidator.app serves a website of its own over HTTPS. It answers on IPv4 only, with a valid TLS certificate and MX records for mail.

5 other domains share an IP address with it.

The most recent crawl returned the page title “HTML Validator Google Chrome Browser Extension” and 9,768 bytes of HTML.

Domain properties

Property	Value	Explanation
Top-level domain	.app	Statistics for all domains we know under this TLD.
Has website	yes	A website is hosted under the domain, which does not redirect to an external domain.
Has MX-record	yes	The domain has an MX record.
External redirect	no	The domain redirects to another domain.
Redirect to https	yes	The domain redirects to https.
Redirect to www.	no	The domain redirects to www.domain.
Only with www.	no	The domain can only be reached with the subdomain "www".
Only DNS, no website	no	There are no A or AAAA records in DNS.
IP-Address	only IPv4	Shows whether the domain only has IPv4 or IPv6 or both.
SSL-Certificate	valid	Shows whether the domain has a valid SSL certificate.
Redirects	0	Number of domains that redirect to this domain.
Reverse IP	5	Number of domains with the same IP(s).

This data through the API

The data on this page is also available as JSON: /lookup for the key facts, /reverseip, /redirect and /similar for the lists, and /dnshistory with Basic and Premium. A free account comes with an API key and 100 calls a day.

curl -X POST https://api.webxtrend.com/v1.0/lookup \
  -H 'Content-Type: application/json' \
  -d '{"token": "YOUR_TOKEN", "query": "htmlvalidator.app"}'

Create a free account Read the API docs

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Websites whose start page offers something similar, found by comparing the text of their start pages, across languages. Near-identical copies, parking pages and error pages are left out. The full list of up to 100 comes through the API: similar websites.

Last SSL certificate

Issuer	Let's Encrypt
Valid from	8/30/2026
Valid to	11/28/2026
Time until expiry	38 days

Last successful crawl

Title	HTML Validator Google Chrome Browser Extension
Description	(not set)
Content-Length	9,768 bytes

Title and description as published by the page itself in its own <title> and <meta name="description"> tags.

DNS history

IPv4 address	Last updated
164.90.199.205	11/8/2024

Mail server	Priority	Last updated
us1-smtp.messagingengine.com	10	7/25/2026
us2-smtp.messagingengine.com	20	7/25/2026
in1-smtp.messagingengine.com	10	11/8/2024
in2-smtp.messagingengine.com	20	11/8/2024

Name server	Last updated
ns1.messagingengine.com	11/8/2024
ns2.messagingengine.com	11/8/2024

The five most recent states of each record type. The full history comes through the API: DNS history.

Most recent redirect domains

No domains found.

Reverse IP neighbours

164.90.199.205 5 domains · here since 9/15/2026

Domain	On this IP since
websitemonitoring.pro	9/14/2026
thesaurusonline.pro	9/15/2026
sqlitebrowser.app	9/15/2026
cmschecker.app	9/14/2026

Sharing an address does not always mean sharing a server: on a CDN or a large hosting platform, millions of unrelated domains answer on the same few addresses. We measured how far that goes in Half the web sits on 276 IP addresses. The complete list of neighbours, also for an IP address, comes through the API: reverse IP lookup.

Dive into our data, search now!