NAPTR Lookup
Query NAPTR (Naming Authority Pointer) records for a domain. NAPTR powers ENUM, SIP and other URI-driven service discovery patterns.
About the NAPTR Lookup Tool
The NAPTR Lookup tool queries Naming Authority Pointer records — a general-purpose DNS record (RFC 3403) used to rewrite a name into a URI or another DNS name for service discovery. NAPTR powers ENUM (mapping E.164 phone numbers to SIP URIs at `e164.arpa`), S-NAPTR/U-NAPTR for SIP/XMPP delegation, and various vendor discovery schemes.
Every NAPTR record carries an order and preference (for iteration), a flags field ('S' for SRV lookup, 'A' for A/AAAA, 'U' for URI rewrite, 'P' for protocol-specific), a service string (e.g. `SIP+D2T` for SIP over TCP), a regexp for substitution rewriting, and a replacement domain. Clients pick the lowest-order group, filter by matching service, apply the regexp, and continue resolution.
Use NAPTR Lookup to debug SIP/VoIP provisioning failures, verify ENUM entries for phone-number routing, or inspect how a domain publishes its discovery graph. Pair with our SRV Lookup — the two often work together when the NAPTR flags field is 'S'.
How to use this tool
- 1Enter the required value in the input field above (domain, IP, URL, or text depending on the tool).
- 2Click the action button to run the check — results are computed instantly from our edge network.
- 3Review the parsed output, key fields and any warnings shown in the result card.
- 4Copy the result, share the page URL, or jump to a related tool from the sidebar to continue debugging.
Key features
- Parses order, preference, flags, service, regexp and replacement
- Sorted by order ascending
- Handles SIP, ENUM, S-NAPTR, U-NAPTR schemas
- Runs over DoH