Result appears here after you select
{ } How it works
What it is
Check whether an IPv4 address is on common email blocklists (Spamhaus, SpamCop, and more).
How it works
DNS Blacklist (DNSBL) Check works on the text you provide. Select Process ▸ and it runs entirely in your browser — nothing is uploaded to a server — then shows the result in the Output panel.
Input
- IP address — paste or type your input in the left panel (use Sample for an example)
Output
TXT text — copy or download it from the Output panel.
{ } FAQ
Is my data uploaded to a server?
No. Everything runs locally in your browser — your files never leave your device.
Can I process more than one file at once?
This tool works on one input at a time.
Is this tool free?
Yes — it’s completely free and needs no sign-up.
Is my lookup private?
Your query is sent to a public DNS-over-HTTPS resolver (Cloudflare 1.1.1.1) to answer it. No files are involved and nothing is stored.
Why might results differ from my computer?
Resolvers cache records for the record’s TTL, so a very recent change can take time to appear everywhere. Use the DNS Propagation tool to compare resolvers.