Check modes

DomainRadar offers four check modes. They differ in how authoritative the answer is, how long it takes, and how much it costs.

Every check flows through the same pipeline – cache → Bloom → DNS → RDAP → WHOIS – stopping at the first method that gives a definitive answer for the mode you picked.

Bloom

A probabilistic check against pre-built filters of registered domains for eligible TLDs.

Latency: sub-millisecond. No network call.
Accuracy: zero false negatives (if Bloom says "free", it's free) and a ~0.000001% false-positive rate (extremely rarely, Bloom says "taken" for a free domain – the next mode catches it).
TLDs covered: the most common (.com, .net, .org, plus a growing list). Other TLDs cascade to DNS.
Cost: the cheapest tier.
Best for: giant pools of candidate names where you only care about availability.

If Bloom says "taken" with high confidence and you don't need the registrar data, you're done.

Verified (DNS)

A real DNS lookup to confirm availability.

Latency: tens to hundreds of milliseconds.
Accuracy: 0% false positives. If a domain resolves DNS records, it's taken.
TLDs covered: all.
Cost: a step up from Bloom.
Best for: when you need certainty about availability for TLDs Bloom doesn't cover, or when you don't trust probabilistic answers.

Info

Verified availability plus parsed registration data: registrar, creation date, last update, expiry, status flags.

Latency: hundreds of milliseconds (one RDAP query).
Cost: higher than Verified.
Best for: "is it taken, and if so, what do I know about it?" – e.g., is the expiry close enough to consider waiting it out, who's the registrar.

The underlying source is RDAP (modern WHOIS) where the registry supports it, falling back to legacy WHOIS otherwise.

Full

Info plus the raw, unparsed WHOIS / RDAP response, plus historical snapshots.

Latency: comparable to Info.
Cost: the highest tier.
Best for: legal investigations, brand teams diffing ownership over time, evidence collection.

Every Full check is persisted as a permanent historical snapshot, so future Full checks of the same domain show ownership changes.

How DomainRadar picks the method

You request a mode; DomainRadar runs the cheapest method that can answer at that level of detail:

Bloom mode asks Bloom first; if inconclusive, escalates to DNS.
Verified mode asks DNS directly.
Info mode asks Bloom + DNS to determine availability, then RDAP for details.
Full mode asks RDAP + WHOIS for the full record.

You're billed for the method that answered, not every step. A Full check that resolves via Bloom (because the domain was free and Bloom already told us) is charged at the Bloom rate, not Full.