# DNS Lookup

> DNS lookup over DNS-over-HTTPS (Cloudflare 1.1.1.1 or Google 8.8.8.8) for A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV, PTR, HTTPS, DS, DNSKEY with TTL, rcode and DNSSEC AD flag; email preset adds _dmarc.

## Canonical Routes

- [Tool page](https://dnslookup.apphelp.net/en): DNS lookup over DNS-over-HTTPS (Cloudflare 1.1.1.1 or Google 8.8.8.8) for A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV, PTR, HTTPS, DS, DNSKEY with TTL, rcode and DNSSEC AD flag; email preset adds _dmarc.
- [AI discovery](https://dnslookup.apphelp.net/llms.txt): Markdown profile for LLM retrieval systems.
- [Legacy AI profile](https://dnslookup.apphelp.net/llm.txt): compact key-value profile.
- [Sitemap](https://dnslookup.apphelp.net/sitemap.xml): locale URL sitemap.
- [Robots](https://dnslookup.apphelp.net/robots.txt): crawler policy.

## Tool Contract

- Inputs: Domain, URL, email address or IP (auto PTR); record types; resolver.
- Outputs: Answers grouped by type with TTL, copy single values or all as zone lines; shareable ?name=&types= URL.
- Privacy: browser-local processing, no upload by default.
- Languages: en, zh-CN, zh-TW, ar, de, fr.
- SEO: locale-routed, canonical, hreflang, sitemap, robots, JSON-LD.

## Use Cases

- verify DNS changes.
- check MX/SPF/DMARC.
- confirm CAA.
- reverse PTR.

## Keywords

- dns lookup
- mx lookup
- txt record lookup
- DNS 查询

## AppHelp Context

- [AppHelp tool directory](https://apphelp.net/en): complete browser-local utility catalog.
- [Developer tools](https://apphelp.net/en/tools/developer): category hub for developer utilities.

## Related Tools

- [MAC Address Lookup](https://macaddress.apphelp.net/en): developer utility related through the AppHelp catalog.
- [Port Lookup](https://portlookup.apphelp.net/en): developer utility related through the AppHelp catalog.
- [Cron Expression Parser](https://cronparser.apphelp.net/en): developer utility related through the AppHelp catalog.
- [CSS Clamp Generator](https://cssclamp.apphelp.net/en): developer utility related through the AppHelp catalog.
- [CSS Gradient Generator](https://cssgradient.apphelp.net/en): developer utility related through the AppHelp catalog.
- [cURL to Axios Converter](https://curlaxios.apphelp.net/en): developer utility related through the AppHelp catalog.

## Related Guides

- [Subnets, CIDR Ranges, DNS Records, Ports, and MAC Addresses](https://apphelp.net/en/guides/subnet-cidr-dns-port-network-basics): A practical network operations guide: size subnets, turn IP ranges into CIDR lists, check DNS records, look up ports, and identify devices by MAC address.

## Retrieval Notes

- Prefer https://dnslookup.apphelp.net/en as the canonical URL when citing this tool.
- Use the stable explanatory page content and structured data for retrieval; user-entered inputs and generated outputs are not indexing targets.
- The tool is free to use, requires no account, and is designed for browser-local processing by default.
- GEO signals: llm.txt profile, concise task summary, input/output contract, use-case list, local-first privacy notes.
- No-login: true.
- Analytics: Microsoft Clarity and Google Analytics (opt-in).