Your files stay on your device

SPF checker

Look up a domain's SPF TXT record over DNS-over-HTTPS, parse its mechanisms, expand include, a, and mx mechanisms recursively to count DNS lookups against the RFC 7208 limit of 10, and warn on multiple records, syntax errors, and permissive all choices.

Type a domain and press Check SPF
The record is fetched live, parsed term by term, and its DNS lookups are counted against the RFC 7208 limit of 10 .

SPF is the first leg of email authentication. The record lists which servers may send for a domain, and the count matters because a receiver gives up with a permanent error once a check passes ten DNS lookups, which silently rejects every message from that domain. This page reads the record, expands every include, a, and mx term, and counts the lookups the way a receiver would. It is an audit, not a full evaluation: there is no sender IP here, macros like % { i } are counted but never expanded, reverse DNS for ptr terms is never resolved, and the DMARC policy, DKIM signatures, and the mail servers themselves are other checks entirely.
OptionsCheck SPF

More network tools

- Live DNS lookup (/network/dns)
- DNS explainer (/network/dns-explain)
- RDAP lookup (/network/rdap)
All network tools (/network)

Was this tool useful?
YesNo

Canonical HTML: https://nutter.tools/network/spf-checker
Markdown version: https://nutter.tools/network/spf-checker.md
Plain-text version: https://nutter.tools/network/spf-checker.txt
Agent index: https://nutter.tools/llms.txt