Free Diagnostic Tools

Fast, free checks for your domain, website and email — run from the same global infrastructure that powers WatchFor monitoring. No signup, no setup, just the answer.

Smart Website Checker

Drop in any URL and get a complete picture of your website's health in seconds — is your domain about to expire, is HTTPS set up right, is your DNS in good shape, is your email protected from spoofing? One scan, one easy-to-read scorecard, no signup.

  • Domain expiry & WHOIS
  • HTTPS + SSL certificate
  • DNS records
  • CDN detection
  • Email security (SPF, DKIM, DMARC)
  • HTTP/2 & HTTP/3 support
Run the check
Core Web Vitals Checker

Run a full Google Lighthouse audit on any URL and see what real users feel — Largest Contentful Paint, Cumulative Layout Shift, Time to Interactive, plus the loading filmstrip frame-by-frame and the top opportunities to fix. The same metrics PageSpeed Insights uses for your search ranking.

  • Performance, Accessibility, SEO scores
  • Largest Contentful Paint (LCP)
  • Cumulative Layout Shift (CLS)
  • Total Blocking Time + TTI
  • Loading filmstrip frame-by-frame
  • Top fixes ranked by impact
Run the check

DNS

Network

Web

Email

Why these instead of MXToolbox or dig?

Free diagnostics aren't new — MXToolbox, dnschecker.org and dig have covered this for years. Here's where ours are different:

  • Real infrastructure. Every check runs from the same global prober fleet that powers our paid monitoring — not a single VPS that throttles after a few hundred requests. Geographic spread and headroom included.
  • Honest results. No upgrade-to-see-more gates, no ad clutter, no fake-warning upsells. You get the exact same output our paying customers see — just without saved history and always-on monitoring.
  • One click to keep watching. If a check finds a problem, turn on 24/7 monitoring for it right from the result — same tool, same infrastructure, no copy-pasting into a second product.

Prefer the terminal? dig, mtr and openssl still win for scripting and exact protocol control. These shine when you want to share a result, check from another location, or skip remembering the flags.

How the tools work

Every tool runs the same probe under the hood. You click Run, we rate-limit the request by IP, hand it to our global prober fleet to do the real protocol-level check (DNS query, TCP handshake, ICMP echo, TLS, HTTP…), and render the result. Probes are written in Go, run with sane 5–10s timeouts, and return their native output — not a reformatted-for-marketing summary.

A few things we deliberately don't do:

  • We don't save your queries. Just enough is kept to enforce rate limits (IP + tool + time) — there's no searchable log of what you checked.
  • We don't run from your browser. The check happens on our servers, so the result is free of your ISP, firewall, VPN or extensions. For the browser view, use DevTools.
  • We don't oversell one check. A single run is one moment from one place — intermittent or regional issues won't always show. If it matters, monitor it continuously.

Run this check on every change, not just once.

Get alerts the moment something breaks — across HTTP, DNS, SSL, RDAP, ping, blacklist and more. Free forever for 10 monitors. No card.

Start free

Frequently asked questions

Are these tools really free, or is there a hidden catch?
Free, no signup, no credit card. We rate-limit per IP (30 requests/hour shared across tools, 10/hour for DNS Propagation since it fans out to every region at once) to keep abuse manageable — that's the only constraint. The free tools run on the same prober infrastructure that paying WatchFor customers use for continuous monitoring; the difference between free and paid is volume and continuity, not feature gating.
How are these different from MXToolbox, dnschecker.org, or dig from the terminal?
Same underlying protocols, different scope and quality. We run from real production prober regions (not from your browser, not from a single VPS). Output is consistent across tools (same result panel components used in the paid product, no ads, no upsells in the result itself). And every check is one click away from continuous 24/7 monitoring if the answer matters beyond the current incident. Terminal dig and mtr give you the same data — these tools win when you want to share the result with a colleague or run from a different geographic vantage.
Do you log my queries?
We log enough to enforce rate limits (caller IP + tool slug + timestamp) and for debugging if something breaks. We do NOT store the targets you queried in any long-term database, and we don't sell or share query data. Each tool run is ephemeral — once we send you the result, we don't retain it.
Can I check my private internal hostname?
No — we run from public infrastructure on the public internet. Private DNS names (*.internal, *.local, RFC1918 IPs) are blocked at the input layer. If you need to verify private/internal connectivity, the paid plan supports private prober regions you deploy inside your own VPC.
Why is one tool rate-limited harder than the others?
DNS Propagation. A single check fans out to 14+ prober regions simultaneously, so one request costs as much as ten regular checks. We give it 10/hour per IP (vs 30/hour for everything else) so the regional fleet stays available for paying monitoring traffic without throttling.
What's the difference between the free tool and the same check inside the paid product?
The probe is identical — same code, same regions, same answer. The paid product adds continuity (the check runs every minute, not once when you click), alerting (you get notified when results change), history (look at how the answer has drifted over weeks), team access, status pages, and the rest of the 21-monitor-type catalogue. Free tools are the diagnostic; paid is the always-on version.
Can I embed these tools in my own site or share results with a link?
Sharable result links are on the roadmap — each successful check will produce a permanent URL that anyone can open without re-running. Embed widgets aren't planned in the short term but a public REST API for the most common tools is being evaluated. Open a request if you want a specific tool API.
What if I need higher rate limits for legitimate use?
Sign up free — authenticated users on any plan get higher per-user limits and access to the in-app toolbox with persistent history. If you're integrating these into your own product or doing security research, contact us with a use case and we'll work out something sensible.