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DNS Propagation Checker

DNS Propagation Checker

Compare results, latency, and error status across multiple recursive DNS and DoH providers. Great for diagnosing propagation delays and resolution forks.

After modifying DNS records, domain migration, or switching DNS servers, it usually takes minutes to 48 hours for records to propagate globally (propagation) due to TTL caching at each level of recursive resolvers. During this period, users in different regions may resolve to different results. This tool queries multiple global public DNS resolvers in real-time, supports traditional DNS, DoH, DoT protocols, simultaneously checks multi-type records (A/AAAA/CNAME/MX/NS/TXT etc.) and TTL remaining time, helping you quickly determine whether DNS changes have taken effect globally.

Related

DNS Lookup

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IPv6 Toolbox

WHOIS Lookup

SSL Certificate Checker

Use Cases

  • After modifying website A records or switching servers, use multi-node checks to confirm whether global resolvers have updated to new IP addresses, avoiding partial user access failures
  • After configuring mailbox MX/SPF/DKIM records, verify whether TXT and MX records propagate globally to ensure mail delivery is normal
  • After enabling DoH/DoT encrypted DNS, use protocol switching to verify whether DNS over HTTPS and DNS over TLS resolution results are correct
  • When SSL certificate issuance fails (DV certificate requires DNS verification), use this tool to confirm whether _acme-challenge CNAME or TXT records have propagated globally
  • When CDN switching or domain migration causes access anomalies, compare resolution results from different resolvers to determine if it's a DNS cache problem or origin issue

Features

  • Multi-record type support: Query A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, PTR nine record types, covering common DNS resolution scenarios
  • Global multi-node check: Built-in multiple global public DNS resolvers (Google/Cloudflare/Quad9/OpenDNS/114DNS/Alidns/Tencent DNS) across different regions
  • Multiple resolution protocols: Support traditional DNS (53/UDP), DNS over HTTPS (DoH), DNS over TLS (DoT) three protocol checks
  • Common domain presets: Built-in quick presets for google.com, cloudflare.com, github.com, example.com, one-click verification
  • Resolver presets: Built-in Google 8.8.8.8, Cloudflare 1.1.1.1, Quad9 9.9.9.9, OpenDNS, 114DNS, Ali DNS, Tencent DNS and other common resolvers
  • One-click results copy: One-click copy DNS diagnostic results for pasting into operation records, ticket systems or technical reports

How to Use

  1. Enter the domain name to query in the input box (e.g. example.com), or click preset domain buttons (google.com/cloudflare.com etc.) for quick input
  2. Select record type: default is A record; can switch to AAAA/CNAME/MX/NS/TXT/SOA/CAA/PTR
  3. Select DNS resolvers: check multiple global public resolvers for simultaneous query, or use built-in resolver presets for quick selection
  4. Select resolution protocol: default is traditional DNS (53 port), can switch to DoH (DNS over HTTPS) or DoT (DNS over TLS)
  5. Click "Check DNS Propagation" button to see resolution results, IP addresses, TTL values and status from each node
  6. Use "Copy Results" button to copy diagnostic summary to clipboard

FAQ

How long does DNS propagation usually take?

<p>Depends on TTL settings and cache levels at each recursive resolver. Typically 5 minutes to 48 hours. After changing records, resolvers that have already cached the old record will wait for TTL expiry before fetching new records. Setting TTL lower (e.g. 300 seconds) 24 hours before migration can speed up propagation.</p>

Why do different DNS resolvers return different results?

<p>During propagation, some resolvers have cached old records while others have fetched new ones. Additionally, different resolvers are deployed in different regions, using different authoritative NS nodes, and may be affected by EDNS Client Subnet (ECS) or geographic DNS policies, leading to different resolution results. This is normal; waiting for TTL expiry will achieve consistency.</p>

What's the difference between DoH and traditional DNS?

<p>Traditional DNS uses UDP port 53 for plaintext transmission; ISPs or network operators can see or even tamper with DNS queries. DoH (DNS over HTTPS) encapsulates DNS in HTTPS traffic (port 443), same as normal web browsing traffic, effectively preventing DNS hijacking and surveillance. DoT uses TLS encryption on port 853 with similar security but different port.</p>

Why do NS records take so long to propagate?

<p>NS records are usually cached by top-level domain servers and recursive resolvers with longer default TTLs (often 48 hours or more). After changing NS servers, global full propagation usually takes 24–48 hours; this is normal. During this period, some users use new NS while others still use old NS. Ensure both old and new DNS servers have consistent records during the period.</p>

Does this tool query from my browser or the backend?

<p>This tool directly queries multiple public DNS resolvers from the user's browser (using DoH protocol where supported), representing the resolution results you see locally. Different users in different network environments may see different results due to CDN geo-DNS.</p>

Why do AAAA (IPv6) records sometimes return nothing?

<p>Many domain names don't have IPv6 records configured (no AAAA records); some resolvers may have incomplete IPv6 support or IPv6 routing issues. This is normal — if a domain hasn't deployed IPv6, AAAA queries return empty.</p>

Will CNAME records hide other records?

<p>Yes. Per DNS standards, if a name has a CNAME record, it cannot have other record types (except DNSSEC-related records). When a CNAME exists, resolvers continue resolving the target domain name, returning records of the final target. This is why www subdomains often use CNAME pointing to main domain or CDN domain.</p>

术语表

A Record
Address record, mapping domain names to IPv4 addresses (e.g. example.com → 93.184.216.34). The most commonly used record type.
AAAA Record
IPv6 address record, mapping domain names to IPv6 addresses (e.g. example.com → 2606:2800:220:1:248:1893:25c8:1946).
CNAME Record
Canonical Name record, pointing one domain name to another domain name (alias). E.g. www.example.com → example.com.
MX Record
Mail Exchange record, specifying mail servers receiving email for the domain, with priority values (lower number = higher priority).
NS Record
Name Server record, specifying authoritative DNS servers for the domain.
TXT Record
Text record, storing arbitrary text information, commonly used for SPF, DKIM, DMARC email verification and domain ownership verification.
TTL (Time To Live)
Cache duration in DNS records (seconds), telling resolvers how long to cache before re-querying. Shorter TTL = faster propagation when changing records.
DoH (DNS over HTTPS)
DNS over HTTPS protocol, encapsulating DNS queries in HTTPS traffic (port 443), preventing ISP-level DNS hijacking and eavesdropping.
DoT (DNS over TLS)
DNS over TLS protocol, encrypting DNS queries using TLS (port 853), providing similar security to DoH with different implementation.
Recursive Resolver
Recursive DNS server (also called local DNS), responsible for receiving user query requests and iteratively querying from root/top-level/authoritative servers, returning final results to users.

Common Global Public DNS Resolver Reference

Google DNS8.8.8.8YesYesGoogleGlobally deployed, fast response, supports DoH/DoT
Cloudflare DNS1.1.1.1YesYesCloudflarePrivacy-first, claims not to log user IP
Quad99.9.9.9YesYesQuad9 FoundationBlocks malicious domains, security protection
OpenDNS208.67.222.222YesYesCiscoSupports content filtering and phishing protection
114DNS114.114.114.114NoNo114DNSDomestic high-speed public DNS (China)
Ali DNS223.5.5.5YesYesAlibaba CloudAlibaba Cloud public DNS, domestic nodes
Tencent DNS119.29.29.29YesNoTencent CloudDNSPod public DNS, quick domestic resolution
Baidu DNS180.76.76.76NoNoBaiduBaidu public DNS

TTL Value Settings and Propagation Time Reference

3005 minutesEmergency migration, pre-change preparation5–15 minutesIncreases authoritative DNS query load
60010 minutesPlanned migration window10–30 minutesGood balance of propagation speed and load
180030 minutesRegular adjustment30–60 minutesGeneral purpose TTL
36001 hourDaily operation default1–2 hoursMost commonly used value
8640024 hoursLong-term stable records24–48 hoursDo not set before migration; cache lasts long
6048007 daysRoot domain/NS records48–72 hoursVery long cache, only for very stable records

Authoritative References

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