Free Tools
Website & Server Tools
Free tools to check SSL certificates, domain expiration, DNS records, nameservers, API health, server latency, redirect chains, and website uptime. No signup required.
SSL Certificate Checker
Check any website's SSL certificate instantly. See expiration dates, issuer details, TLS version, certificate chain, and security grade.
- Certificate validity & expiration
- TLS protocol version
- Issuer & subject details
- Security grade breakdown
Domain Expiration Checker
Look up any domain's registration details. See expiry date, registrar, nameservers, and WHOIS data, all from RDAP and WHOIS databases.
- Domain expiry date & countdown
- Registrar & nameservers
- WHOIS creation & update dates
- Registry status codes
DNS Lookup Tool
Look up all DNS records for any domain. Check A, AAAA, MX, NS, TXT, SOA, CAA, and CNAME records with email security analysis and a DNS health grade.
- All record types (A, AAAA, MX, NS, TXT, SOA, CAA)
- Email security analysis (SPF & DMARC)
- DNS health grade
- TTL values & SOA details
Nameserver Lookup
Check the nameservers for any domain. See NS records, the IP addresses behind each nameserver, the DNS provider running them, and a delegation health grade.
- NS records with IPv4 & IPv6 addresses
- DNS provider detection
- Redundancy & network diversity check
- SOA record & consistency check
API Status Checker
Test any API endpoint's health. Check response time, HTTP status, security headers, CORS configuration, and redirect chains in real time.
- Response time & status code
- Security headers audit
- CORS configuration check
- Redirect chain analysis
Ping Test
Measure latency, packet loss, and jitter to any server or website. TCP-based ping from your browser, with no command line needed.
- Latency (min / avg / max)
- Packet loss percentage
- Jitter measurement
- Multiple ping rounds
Redirect Checker
Trace the full HTTP redirect chain for any URL. See every hop, status code, Location header, and response time. Finds broken or unnecessary redirects.
- Full redirect chain visualization
- Status codes for every hop
- Response time per redirect
- Response headers inspection
Uptime Checker
Comprehensive website health check. Analyzes DNS, SSL, redirects, response time, security headers, and content health with detailed grades.
- DNS, SSL & redirect analysis
- Security headers audit (HSTS, CSP)
- Performance metrics (TTFB, compression)
- Overall health score (A+ to F)
Start from the symptom
Most of these failures look identical from the outside: the site is “down”. What separates them is which layer stopped answering. Find the symptom you actually have, and the tool that confirms it.
Browser warns visitors the connection is not private
The certificate expired, or the chain is missing an intermediate so only some clients trust it.
SSL Certificate CheckerThe site resolves for you but not for someone else
A stale record, or the registrar and the DNS host disagree about which nameservers are authoritative.
Nameserver LookupEmail to your domain silently stops arriving
An MX, SPF, DKIM or DMARC record was edited or dropped. None of it breaks the website, so nothing else alerts.
DNS Lookup ToolThe domain stops working entirely, all at once
The registration lapsed. Registrar reminders go to whichever mailbox registered it, which is rarely the one you read.
Domain Expiration CheckerPages load, but slowly, and only sometimes
A redirect chain is adding a round trip per hop, or one hop leaves HTTPS and comes back.
Redirect CheckerThe app is up but an integration reports failures
The endpoint returns 200 with an error body, so anything that only checks status codes sees success.
API Status CheckerConnections feel unstable rather than down
Packet loss or jitter on the path. Averages hide it; the variance is the symptom.
Ping TestSomething is wrong and you cannot narrow it down yet
Start wide. One pass over DNS, TLS, redirects, headers and response time tells you which of the above to open.
Uptime CheckerQuestions
Do these tools need an account?
No. Every tool on this page runs without a signup, an email address, or a trial. Enter a domain and read the result. Continuous monitoring needs an account because it has to store your checks and reach you when one fails, but nothing here does.
What is the difference between a check and monitoring?
A check is one measurement, right now, from wherever the request happens to originate. Monitoring is the same measurement repeated on a schedule from fixed regions, with the history kept so you can tell a blip from a trend, and an alert when the result changes. A check answers whether something is broken. Monitoring is what tells you it broke at 03:12 while you were asleep.
How current are the results?
Every tool queries live: DNS resolvers, RDAP and WHOIS registries, and the target host itself. Nothing is served from a cache of a previous visitor's lookup. DNS answers are still bounded by the TTL on the record, so a change made seconds ago may not have propagated to the resolver that answers.
Can I share or automate a result?
Each tool encodes its input in the URL, so a result page can be pasted into an issue or a chat and it will re-run for whoever opens it. For anything scripted, use the REST API instead of the browser tools.
Why Use These Tools?
Instant Results
Get detailed results in seconds. No account, no email, no paywall. Just enter a domain and go.
Developer Friendly
Built for developers and sysadmins. Copy results, download reports, and share via URL parameters.
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