About DNSbyte
Free DNS and infrastructure diagnostics for developers and sysadmins.
What is DNSbyte?
DNSbyte is a free toolkit for DNS diagnostics, mail configuration checks, propagation analysis and security inspection. Fifteen tools in one place - no account, no registration, no data stored.
All lookups run in real time against live data. Results are cached briefly to reduce server load, but nothing is kept beyond that window and no personal information is collected.
Rate limits apply to prevent abuse. See the Privacy Policy and Terms and Conditions for full details.
The tools
Lookup
- WHOIS Lookup - domain registration details, registrar information and expiry dates
- DNS Records - query any record type against live resolver data
- Reverse DNS - PTR record lookup for any IP address
- MX Checker - mail exchange records and priority values
- SPF / DKIM / DMARC - full mail authentication policy check
- Email Headers - parse raw headers to trace delivery path and flag issues
Analysis
- DNS Propagation - check how a record is resolving across global resolvers
- DNS Checker - compare DNS responses across multiple providers
- TTL Inspector - inspect time-to-live values for a domain's records
- Zone Health - check for common DNS zone configuration issues
Security
- SSL Certificate - certificate details, chain, expiry and validity
- HTTP Headers - inspect security and response headers for any URL
- Blacklist Check - test an IP or domain against common DNS blacklists
- DNS over HTTPS - run a DoH query against major resolver endpoints
- Reachability - test whether a host or IP is reachable from the server