HTTPS record check
Looks up the HTTPS record set and shows each record's priority, target, mode, alpn protocols, port, IPv4 and IPv6 hints and whether ECH is published, and reports records that cannot be read, AliasMode conflicts, missing mandatory keys and no-default-alpn without alpn.
Updated 2026-10-27
What this tool checks
The HTTPS record set of the name is looked up through public resolvers, and each record is read:
- Mode: AliasMode (priority 0) or ServiceMode, with priority and target.
- Parameters: alpn, no-default-alpn, port, ipv4hint and ipv6hint, and whether ECH is present.
- Consistency: mandatory keys that are missing, no-default-alpn without alpn, and AliasMode beside other records.
How to read the result
Each record is a row, lowest priority first. No HTTPS record is normal for many sites: SVCB_NOT_FOUND is information.
Limitations
- The hints are not compared with the name's A and AAAA records, and the ECH configuration is not decoded.
Use it from code
API reference for HTTPS record check
curl -i "https://api.lookproof.dev/v1/dns/https-rr?domain=example.com"A request without payment is answered with 402 Payment Required and the exact price. See the API reference.
Limits
| Input | Host name |
|---|---|
| Deadline | 10 seconds |
| Freshness | Up to 5 minutes, never longer than the record TTL |
| Price | $0.01 per check |
Findings this tool can report
DNS (3)
- Error
DNS_DOMAIN_NOT_FOUNDThe DNS resolver reported that the domain does not exist. - Warning
DNS_RESOLVER_FAILUREThe DNS resolver returned a server failure. - Warning
DNS_RESOLVER_TIMEOUTThe DNS resolver did not answer in time.
Check (1)
- Warning
CHECK_QUERY_BUDGET_EXCEEDEDThe check stopped after reaching its DNS query limit.
HTTPS and SVCB records (7)
- Warning
SVCB_ALIAS_CONFLICTAn HTTPS AliasMode record sits beside other HTTPS records. - Warning
SVCB_ALIAS_WITH_PARAMSAn HTTPS AliasMode record has parameters, which clients ignore. - Error
SVCB_ALPN_MISSINGAn HTTPS record has no-default-alpn but no alpn parameter. - Info
SVCB_ECHThe HTTPS record publishes an Encrypted Client Hello configuration. - Error
SVCB_INVALIDAn HTTPS record cannot be read. - Error
SVCB_MANDATORY_MISSINGAn HTTPS record lists a mandatory parameter that it does not have. - Info
SVCB_NOT_FOUNDThe name publishes no HTTPS record.
Frequently asked questions
What is an HTTPS record?
A DNS record type (RFC 9460) that tells browsers how to connect before they do: which protocols the server speaks (alpn, such as h3 for HTTP/3), on which port, which addresses to try, and an Encrypted Client Hello key.
What is AliasMode?
A record with priority 0 sends clients to another name, like a CNAME that also works at the zone apex. It should stand alone and carry no parameters: SVCB_ALIAS_CONFLICT and SVCB_ALIAS_WITH_PARAMS.
Is the ECH key shown?
No. The check only reports that the record publishes an ECH configuration (SVCB_ECH); the key itself is not shown or checked.