Privacy policy

1. Data you enter for a check

The domain, the expected value (IP, nameserver, verification code) and the record type are used only to carry out the check.

• The domain is sent to public DNS servers in Vietnam and worldwide (for example those of ISPs, Google and Cloudflare) and to the domain’s own nameservers. This is how DNS works.
• DNS answers are cached for at most 20 seconds so that many people checking the same domain do not overload the DNS servers.
• Domains are counted for 60 seconds to prevent abuse (one domain being checked in bulk).
• We do not write the domain or the expected value to logs and do not link the domain to the person checking it.
• A share link contains the domain and the expected value in its address. Anyone with the link can see it, so only send it to people who need it.

2. Your IP address

• Your IP is used to limit the number of checks (abuse prevention). The original IP is not stored.
• We only store a pseudonym: an HMAC of the IP with a random secret key created anew every day. Each day’s key is deleted after at most 2 days; from then on the IP cannot be recovered from the pseudonym, and pseudonyms of different days cannot be linked to each other.
• Operational statistics are hourly counters only (checks by purpose and outcome, rate-limited checks, response times per DNS server), without domains, IPs or IP pseudonyms.
• Rate-limit counters are deleted after at most 24 hours. Application logs contain only the pseudonym, the kind of check and the processing time, and are kept for 30 days for troubleshooting. The proxy is configured not to log request addresses together with IPs.
• When the system needs to verify that you are not a bot, your browser may show a Cloudflare Turnstile challenge. Cloudflare processes your IP for this.

3. IP lookups

• The IP you look up is matched against the offline databases DB-IP Lite (and IPinfo Lite when available) on our own server.
• To get the host name (PTR) and the registration data (RDAP), the IP is sent to a DNS server and to the regional internet registry responsible for its range (for example APNIC).
• Lookup results are cached for 24 hours per looked-up IP, not linked to the person looking it up.

4. Google Analytics

• We use Google Analytics 4 to understand how the tool is used (for example how many Email checks are made).
• Google Analytics stores cookies only after you press “Accept”. If you have not accepted or have declined, Google only receives cookieless signals to estimate figures (Consent Mode).
• We do not send domains, expected values, IPs or IP pseudonyms to Google. Page addresses are shortened, for example “/website/[domain]”.
• You can change your choice at any time with “Cookie settings” in the footer.
• Your browser keeps your choices (cookie consent, last check purpose) in its local storage; this data is not sent to the server.

5. Processors and storage location

ChkDNS servers are hosted on HVN GROUP infrastructure. We use Cloudflare to deliver and protect the site, and Google for Google Analytics. We do not sell or share data for advertising.

6. Your rights

Under Decree 13/2023/ND-CP you have the right to be informed, to consent or withdraw consent, to access, to request deletion, and to restrict or object to the processing of your personal data. Because we do not store original IPs and do not link domains to users, most data cannot be traced back to a specific person. You can still contact us with questions or requests.

Email kinhdoanh@hvn.vn or call +84 24 9999 7777.

7. Changes to this policy

When this policy changes, we update this page and the date at the top.