FAQ

Common questions about SubnetHistory, its data and its API.

Is SubnetHistory free?

Yes. Website lookups are free, and the API is open at 120 requests per minute per client IP with no key required. Higher volume: [email protected].

Do I need an API key?

No. Every endpoint works without authentication. Any change will be documented here before it is enforced.

Why did my first lookup take so long?

A cold lookup waits on upstream sources and can take tens of seconds. The result is cached and answers in milliseconds afterwards. The streaming endpoint reports progress instead.

The response says some data was still loading

meta.partial is true when a dataset was still being fetched, or failed, as the response was sent. meta.pendingDatasets and meta.failedDatasets separate the two. A pending fetch continues into the cache, so a repeat lookup returns the rest, and the streaming endpoint delivers it on the same connection. A failed source is left alone for a few minutes before it is called again, so repeating sooner returns the same report: meta.retryAfterMs says how long that is. Fields from a dataset that has not arrived read n/a, which is a missing answer and not a zero.

Why does a private or reserved address show almost nothing?

Space such as 10.0.0.0/8, 127.0.0.1 and CGNAT ranges is special use by RFC: no registry holder, no ownership history, no public routing. The report describes the range instead.

How fresh is the data?

Each dataset has its own lifetime. Cached answers revalidate in the background, and every response marks each source with its cache state. See the freshness page.

Can I force a refresh?

The refresh=1 parameter is reserved for operators. Without authorisation it is ignored and the request is served normally.

Who applies the tags?

A person confirms tags, with one exception: a high confidence finding from our own active checks is an objective measurement and confirms on its own. Feeds propose, and a proposal is shown as a suggestion until it is confirmed. Disputes go to [email protected], naming the resource.

Timeline or archive?

The timeline merges registry events, transfers, routing windows and SubnetHistory's own observations. The archive endpoint returns only what SubnetHistory recorded itself: change events and persisted routing observations.

Does SubnetHistory scan networks?

Yes. A lookup can queue its subject for an active check that verifies whether addresses operate as proxies; how the checks are performed is not documented. Absence of a result means not checked, not clean. See Active scanning.

Is IPv6 supported?

Yes. Addresses, prefixes and the ASN views all handle IPv6 alongside IPv4.

Are my searches private?

Searches are logged to operate the service. The public list of recent searches shows the normalised query, its kind and a timestamp, nothing about who searched. Full detail in the privacy policy.

Can I use the data commercially?

Yes, within the rate limit and the terms: use the data lawfully, do not present it as an original measurement, and do not bulk mirror the archive for resale. Sources set their own attribution wording, listed on the Data sources page. There is no SLA.

How do I get in touch?

Email [email protected]. Terms at subnethistory.com/terms, privacy at subnethistory.com/privacy, longer writing at subnethistory.com/blog.