VLANlab
Catalog
ENEnglishJA日本語ESEspañolRUРусскийKO한국어PTPortuguêsZH中文ARالعربية
About
VLANlab
DNS
15 tools
DNS LookupDNS PropagationDNS Health CheckerSPF AnalyzerPTR LookupCAA RecordSRV RecordDNS TraceDNS PrivacyDANE / TLSADNSSEC Checker
BUILDERS
SPF BuilderCloudDKIM GeneratorCloudZone DiffPTR Zone Generator
VLANlab

CALCULATE • LOOKUP • VERIFY

What Is My IP?IPv6 TestSpeed TestHTTP Request Headers
DNS LookupDNS PropagationDNS Health CheckerSPF AnalyzerPTR LookupCAA RecordSRV RecordDNS TraceDNS PrivacyDANE / TLSADNSSEC CheckerSPF BuilderDKIM GeneratorZone DiffPTR Zone Generator
Subnet CalculatorCIDR Range ViewerVLSM CalculatorVLAN PlannerBandwidth CalcIPv6 Subnet CalcIP ↔ BinarySupernet CalcCIDR MergeCIDR to IP RangeCIDR SplitIPv4 → IPv6CIDR OverlapFree IP Space FinderDHCP CalculatorMTU Calculator
WHOIS LookupDomain Age CheckerSubdomain FinderIP GeolocationASN / BGP LookupIP Blacklist CheckReverse IP LookupMAC Address LookupBGP Prefix LookupRPKI / ROA CheckDomain Availability
Email InspectorDKIM CheckerEmail HeadersSMTP Test
SMTP TLS CheckSoon
MX Health CheckEmail SecurityDMARC Generator
Temp MailSoon
Is It Down?SSL/TLS CheckerOpen Port CheckerOG Tag CheckerOCSP CheckerPing / LatencyHTTP InspectorRedirect ChainCSP AnalyzerTech Stack CheckerBetaTracerouteBetaHTTP/2 + HTTP/3robots.txt ViewerSSL Cert DecoderBanner GrabberWebSocket TesterCORS TesterHTTP TimingStructured DataPWA ManifestSEO Auditor
One-Time SecretHash GeneratorPassword StrengthSecurity.txtCT Log SearchAXFR Zone Test
HTTP Sec ScoreSoon
WebRTC Leak TestIP Reputation
JSON FormatterYAML FormatterBase64 / URL EncodeJWT DecoderRegex TesterUnix TimestampCron BuilderUUID / ULIDPunycode / IDNBase ConverterACL Generator
CSS Unit ConverterColor ToolkitGradient GeneratorcURL BuilderURL ParserURL Encoder/DecoderHTTP Status CodesBox Shadow GenFavicon GeneratorQR Code GeneratorFlex & Gridrobots.txt Tester
Text CompareCase ConverterText CleanerText AnalyzerText TransformerList ToolsLorem GeneratorSlug Generator
Cloud VPC PlannerCloud IP RangeSecurity GroupsIAM AnalyzerK8s CIDR PlannerFirewall BuilderHCL FormatterEgress Cost CalcCloud DNS Zone
VM Cost EstimatorSoon
Proxmox Net ConfigVMware Port GroupHyper-V vSwitchVXLAN VNI PlannerKVM Net ConfigXCP-ng NetworkNSX-T Segment
Disposable Email DetectorPhone InspectorTor Exit NodeVPN/Proxy DetectDomain ReputationTyposquat DetectUsername SearchFavicon Hash
GitHub ActionsDockerfile Gendocker-composeArgoCD AppK8s Manifests
About

© 2026 VLANlab

No login · No ads · No tracking

2.63.a76559e

DNS Privacy Checker

Compare DNS results across four public resolvers and test for NXDOMAIN hijacking - a sign of ISP DNS interception.

Examples:

Enter a domain to compare DNS results across public resolvers

Related Tools

DNS Lookup

Query any DNS record type for any domain - A, AAAA, MX, TXT, CNAME, NS, SOA, CAA. Results come from our own neutral resolver.

DNS Propagation

Check whether a DNS change has propagated: query public resolvers worldwide, see them on a map and refresh on a timer.

DNS Health Checker

Audit the DNS setup of any domain and get a letter grade with specific fix hints for each failing check.

About this tool

DNS Privacy Checker tests whether public DNS resolvers agree on your domain and whether NXDOMAIN responses are being hijacked. Queries run against Cloudflare (1.1.1.1), Google (8.8.8.8), NextDNS and Quad9 using DNS-over-HTTPS - an encrypted alternative to plaintext UDP DNS that prevents ISP interception.

NXDOMAIN hijacking is a technique used by some ISPs to redirect failed DNS lookups to ad pages or search engines instead of returning the correct "domain not found" response. The test queries a random subdomain under the IANA-reserved .invalid TLD - which must always return NXDOMAIN per RFC 2606. Any other response indicates the resolver is manipulating DNS responses.

Note: different resolvers returning different IPs for the same domain is normal for CDN-hosted sites - CDNs serve requests from the nearest edge node. This tool only flags inconsistency when some resolvers find a domain and others return NXDOMAIN for the same name.