Monitor one IP address or domain against hundreds of blacklists and reputation data sources, free indefinitely. Real-time alerts the moment a listing appears. No credit card, no time limit.
Most teams discover a blacklist listing the way you would never want to: customers stop receiving email, an ISP forwards a spam complaint, or a deliverability dashboard turns red. By the time the news arrives, the damage is hours old.
A one-shot blacklist check tells you what your reputation looks like right now. Continuous monitoring tells you the moment that changes. The free Generator Labs plan exists because the gap between "right now" and "the moment that changes" is where most deliverability outages live, and it should not require a paid subscription to close.
Same monitoring engine as paid plans. Scoped to one host.
Pick an IP address (IPv4 or IPv6) or a domain. We check it against hundreds of blacklists and reputation systems on a regular cadence and alert you the moment anything changes.
Spamhaus, Barracuda, SpamCop, SURBL, and the rest of the major blacklists. Paid plans add premium sources like Microsoft SNDS, Google Postmaster Tools, and PhishTank. The full list of monitored sources is public.
Email alerts the moment a listing appears or clears. Includes the source that flagged you, why, and the documented removal process when available.
Every check is recorded. Browse the history to spot patterns, share a public report URL with an ISP or customer, and verify your reputation timeline.
Add hosts, query check history, and automate your response through the REST API, with official SDKs for PHP, Node.js, Python, Go, and Ruby.
No card on file, no automatic conversion to paid, no expiry on the free plan. Upgrade later if you need more hosts; otherwise stay on free indefinitely.
Free blacklist tools do different jobs. Pick the one that matches what you actually need.
| Need | One-shot check tools | Generator Labs free plan |
|---|---|---|
| Check my reputation right now | Yes, instantly (try mrdns.com) | Yes, in the dashboard |
| Be alerted when listings change | No, requires manual re-check | Yes, real-time alerts |
| Track history over time | No | Yes, full check history |
| Programmatic access (API) | Limited or none | Full REST API |
| Cost | Free | Free for one host, paid plans for more |
| Sign-up required | No | Email-only signup, no credit card |
Need a one-shot check right now? Run a free blacklist check, or try mrdns.com/blacklist-check. Need continuous monitoring without the price tag? Stay here.
It is permanently free. Monitor one host (an IP address or a domain) indefinitely against hundreds of blacklists and data sources, including Spamhaus, Barracuda, SpamCop, and SURBL, with real-time alerts. No credit card required, no time limit, no auto-conversion to a paid plan.
One host monitored continuously against hundreds of blacklists and reputation data sources, real-time alerts via email, full check history, and access to the public report URL. Same monitoring engine used by paid plans, just scoped to one host.
A one-shot check tells you whether your IP is listed right now. The free plan tells you within minutes when that changes. Listings can happen at any time, and most outages caused by blacklisting are not noticed until customer complaints arrive.
Yes. Upgrade to a paid plan (Professional, Enterprise, or pay-per-check Ultimate) at any time and your existing host, history, and alert settings carry over. No data is lost in either direction if you downgrade.
No hidden ones. Free covers one host, checked every 48 hours against hundreds of blacklists and data sources. Paid plans add more hosts, faster checks, premium sources like Microsoft SNDS, Google Postmaster Tools, and PhishTank, and your own custom sources.
One host, hundreds of data sources, real-time alerts. No credit card required.