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Free website monitoring tools
The same checks Upcheck runs for its customers, open to anyone, one at a time. Each one runs live from outside your network and shows you the evidence, not just a verdict.
Uptime & HTTP
- Is my website down?Requests your site live from Cloudflare's network and reports the HTTP status, response time, and where redirects landed, so you know whether it's down for everyone or just you.
- HTTP headers checkerRequests any URL and lists the response headers it came back with, then checks which of the common security headers are set and which are missing.
- Redirect checkerFollows redirects one hop at a time and shows each status code, each location, and where the chain finally lands, so a loop or a temporary redirect can't hide.
- HTTP status code checkerChecks the HTTP status code of up to ten URLs at once, follows their redirects, and explains every code, so a stray 404, 500, or redirect chain shows up in one pass.
- Security headers checkerScans a URL for HSTS, Content-Security-Policy, X-Frame-Options, and the other headers browsers enforce, grades them A+ to F, and says what to fix.
- TTFB testTimes how long a URL takes to send its first byte on a fresh request, redirects included, and on repeat requests, rated against web.dev's thresholds.
- Uptime calculatorConverts an uptime percentage into the downtime it allows per day, week, month, and year, or works backwards from minutes of downtime to the percentage it implies.
DNS
- DNS lookupLooks up A, AAAA, CNAME, MX, NS, TXT, SOA, and CAA records for a name from a public resolver, with the TTL on every record so you can see how long caches will hold it.
- A record lookupReturns the IPv4 and IPv6 addresses a name currently resolves to, along with any CNAME it passes through on the way.
- CNAME lookupShows the CNAME record for a name and the alias chain it follows, which is how you confirm a www, CDN, or SaaS hostname points where it should.
- NS lookupLists the nameservers a domain delegates to, so you can confirm a DNS provider change took and that every visitor's resolver will ask the right servers.
- TXT record lookupFetches all TXT records for a name, which is where SPF, DKIM, DMARC, and domain-verification strings live, and shows them whole rather than split into 255-byte chunks.
- CAA record lookupFinds the CAA records that restrict which certificate authorities can issue for a name, climbing to the parent domain the way a CA does when the exact name has none.
- Reverse DNS lookupLooks up the hostname an IPv4 or IPv6 address maps back to, which mail receivers check before accepting a connection from a server.
- DNS propagation checkerAsks 12 public resolvers for the same record at once and shows which of them agree, so you can watch a DNS change spread and spot caches still serving the old answer.
Email DNS
- MX lookupLists a domain's mail exchangers in priority order, so you can confirm mail is routed to the right provider and nothing stale is left over from a migration.
- SPF checkerFetches a domain's SPF record, follows every include, counts the DNS lookups against the limit of ten, and flags the mistakes that make receivers ignore the record.
- DMARC checkerReads the DMARC record at _dmarc, explains each tag, and flags a missing policy, a monitor-only p=none, or a record with nowhere to send reports.
- DKIM checkerLooks up a domain's DKIM keys by selector, or tries the common ones for you, then decodes the key length and flags revoked keys, short keys, and test mode.
Domains & IPs
- WHOIS lookupLooks up a domain or IP address over RDAP, the successor to WHOIS: registrar, expiry date, and status for domains; owning network, range, country, and abuse contact for IPs.
- Typosquatting checkerGenerates hundreds of lookalike domains for yours, from typos and look-alike characters to other TLDs, and shows which are registered and whether they serve a website or receive email.
A single check answers a question. Monitoring keeps answering it.
Most tools here are one of the probes Upcheck runs automatically for the websites it monitors: the uptime request every 5 minutes, the certificate read twice a day, the DNS resolution every 6 hours, the registration lookup daily. Running one by hand costs us nothing worth charging for, and it shows you exactly what the monitor would see.
What a one-off check can't do is notice when the answer changes. That is where uptime monitoring and SSL monitoring come in: the same checks, re-run on a schedule, with an alert to your team when one fails.
Stop checking by hand.
Add your websites to Upcheck and get alerted by email, Slack, Discord, Teams, or webhook the moment one of these checks fails.