Diagnose any domain, host, or IP.
Free DNS, email, SSL/TLS, network and security checks — run one, or point the Super Scanner at a domain and get every result plus one overall score. No signup, no limits.
looking for one specific check? browse the tool directory ↓
What are you troubleshooting?
Each goes straight to the check that answers it. Not sure? Run the Super Scanner above.
Popular tools
Tool directory
Already know what you are troubleshooting? Every tool, filterable, one category at a time.
Why NET Tools: DNS, Email, SSL & the Super Scanner
NET Tools is a free, browser-based toolkit for diagnosing DNS, email, SSL/TLS and network problems, the same class of checks system administrators, developers and IT teams reach for daily, without installing anything or memorising dig, openssl or traceroute syntax.
Every lookup runs server-side in real time: DNS record checks (A, AAAA, CNAME, MX, NS, TXT, SOA, CAA), email authentication and deliverability (SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT), an SSL/TLS checker that grades a site from A+ to F, and core network utilities like ping, traceroute and a port checker. A DNS blacklist checker, a subdomain takeover scanner and a full HTTP security-headers audit round it out.
Rather than dumping raw output, every result explains what was checked, what was found, why it matters and how to fix it, so a DMARC policy of p=none or a missing CAA record means something even if you are not deep in DNS internals every day. For an at-a-glance health check across DNS, email, website and security posture at once, the Super Scanner runs everything together and returns one overall score.
Nothing here requires an account. Create a free one only for scheduled Domain Monitors that re-run the scan on a timer and track a domain's score over time, or to call any tool from a script via the public API.
Frequently asked questions
Is NET Tools really free?+
Yes — every DNS, email, SSL/TLS, network, and security tool on this site is free, with no signup and no rate limit for normal use. A free account only unlocks scheduled Domain Monitors and API keys.
Do I need to create an account?+
No. Every diagnostic tool works immediately without logging in. An account is only needed for Domain Monitors (recurring scans with score history over time) and for generating an API key.
What does the Super Scanner check?+
It runs every DNS, email, website, and security tool against a domain in one pass — A/MX/NS records, SPF/DKIM/DMARC, SSL/TLS certificate health, HTTP security headers, and blacklist/subdomain-takeover checks — and combines the results into one overall score with a full breakdown per category.
What's the difference between the individual tools and the Super Scanner?+
The individual tools, like the SPF checker or SSL/TLS checker, are for a focused, one-off check when you already know what you're troubleshooting. The Super Scanner runs all of them at once — better for a general health check or a before/after comparison when making DNS or server changes.
Is my data stored or shared?+
Public lookups aren't tied to your identity. If you're logged in, your Super Scanner history and Domain Monitor results are saved to your account so you can track a domain's health over time — that's the only data kept beyond what's needed to run the check.
Can I use NET Tools programmatically?+
Yes — every tool is also a plain HTTP JSON API. Public lookups need no authentication; anything tied to your account (monitors, teams, dashboard) needs a free API key. See the full API reference for every endpoint.