Historical DNS Records

Robtex lets you view historical and past DNS records for any domain. The passive DNS database has tracked observed DNS answers since around 2013, coverage varies by domain, and the lookup is free with no login required.

What passive DNS means

Passive DNS is observed DNS resolution history. It records that a resolver or sensor saw a domain return a value at a point in time, such as an A record pointing to an IP address, an MX record pointing to a mail server, or an NS record pointing to a nameserver.

Passive DNS is different from registrar and WHOIS history. WHOIS history follows registration events such as registrar, registrant, creation date, expiration date, and nameserver delegation metadata. Passive DNS follows resolution behavior, so it can show hosting moves, mail changes, CDN use, former infrastructure, and records that were visible even when the domain registration did not change.

How to use it

Open an example passive DNS history for example.com

Enter a domain name and open the Robtex DNS lookup page. The domain page includes current records and a DNS History section when Robtex has enough observations for a timeline.

What Robtex shows

Robtex groups observed records by type and value, then shows whether each record is active or former. For records with history, the domain page shows first-seen and last-seen dates, observation counts, and a timeline of individual observations. This is useful for finding former origin IPs, nameserver migrations, mail infrastructure changes, and other DNS changes that are not visible in a live DNS query.

When to use historical DNS records

Security teams use historical DNS records to connect domains to earlier infrastructure, investigate phishing or malware campaigns, and find related hosts that shared an IP address or nameserver. Operators use the same history to audit migrations, confirm when a DNS change became visible, and understand why cached or regional answers may have differed during a change window.

API and agent access

Robtex exposes the same kind of DNS intelligence through web pages, APIs, and agent integrations:

Use What Is My DNS Resolver to see which recursive resolver is querying on your behalf. Use What Is My IP when you need to compare the address used by web traffic with the resolver used by DNS traffic.

FAQ

What are historical DNS records?
Historical DNS records are previously observed DNS answers for a domain, such as old A, AAAA, MX, NS, CNAME, or PTR records. They show how DNS answers changed over time.
Is passive DNS the same as WHOIS history?
No. Passive DNS is observed resolution history. WHOIS history is registration history. A domain can move to a new IP address without a WHOIS change, and a WHOIS change can happen without a DNS answer changing.
How far back does Robtex DNS history go?
Robtex has tracked passive DNS since around 2013. Coverage varies by domain and record type because passive DNS depends on what was observed.
Do I need an account or API key?
No. The web lookup is free and does not require login. API and MCP integrations are available for programmatic use.
Can historical DNS records reveal an old origin IP behind a CDN?
Sometimes. If Robtex observed the domain before it moved behind a CDN or proxy, the history may show earlier A or AAAA records. It is evidence of observed DNS answers, not proof of current hosting.