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VLANlab
Testing
21 tools
Is It Down?SSL/TLS CheckerOpen Port CheckerOG Tag CheckerOCSP CheckerPing / LatencyHTTP InspectorRedirect ChainCSP AnalyzerTech Stack CheckerBetaTracerouteBetaHTTP/2 + HTTP/3robots.txt ViewerSSL Cert DecoderBanner GrabberWebSocket TesterCORS TesterHTTP TimingStructured DataPWA ManifestSEO Auditor
VLANlab

CALCULATE • LOOKUP • VERIFY

What Is My IP?IPv6 TestSpeed TestHTTP Request Headers
DNS LookupDNS PropagationDNS Health CheckerSPF AnalyzerPTR LookupCAA RecordSRV RecordDNS TraceDNS PrivacyDANE / TLSADNSSEC CheckerSPF BuilderDKIM GeneratorZone DiffPTR Zone Generator
Subnet CalculatorCIDR Range ViewerVLSM CalculatorVLAN PlannerBandwidth CalcIPv6 Subnet CalcIP ↔ BinarySupernet CalcCIDR MergeCIDR to IP RangeCIDR SplitIPv4 → IPv6CIDR OverlapFree IP Space FinderDHCP CalculatorMTU Calculator
WHOIS LookupDomain Age CheckerSubdomain FinderIP GeolocationASN / BGP LookupIP Blacklist CheckReverse IP LookupMAC Address LookupBGP Prefix LookupRPKI / ROA CheckDomain Availability
Email InspectorDKIM CheckerEmail HeadersSMTP Test
SMTP TLS CheckSoon
MX Health CheckEmail SecurityDMARC Generator
Temp MailSoon
Is It Down?SSL/TLS CheckerOpen Port CheckerOG Tag CheckerOCSP CheckerPing / LatencyHTTP InspectorRedirect ChainCSP AnalyzerTech Stack CheckerBetaTracerouteBetaHTTP/2 + HTTP/3robots.txt ViewerSSL Cert DecoderBanner GrabberWebSocket TesterCORS TesterHTTP TimingStructured DataPWA ManifestSEO Auditor
One-Time SecretHash GeneratorPassword StrengthSecurity.txtCT Log SearchAXFR Zone Test
HTTP Sec ScoreSoon
WebRTC Leak TestIP Reputation
JSON FormatterYAML FormatterBase64 / URL EncodeJWT DecoderRegex TesterUnix TimestampCron BuilderUUID / ULIDPunycode / IDNBase ConverterACL Generator
CSS Unit ConverterColor ToolkitGradient GeneratorcURL BuilderURL ParserURL Encoder/DecoderHTTP Status CodesBox Shadow GenFavicon GeneratorQR Code GeneratorFlex & Gridrobots.txt Tester
Text CompareCase ConverterText CleanerText AnalyzerText TransformerList ToolsLorem GeneratorSlug Generator
Cloud VPC PlannerCloud IP RangeSecurity GroupsIAM AnalyzerK8s CIDR PlannerFirewall BuilderHCL FormatterEgress Cost CalcCloud DNS Zone
VM Cost EstimatorSoon
Proxmox Net ConfigVMware Port GroupHyper-V vSwitchVXLAN VNI PlannerKVM Net ConfigXCP-ng NetworkNSX-T Segment
Disposable Email DetectorPhone InspectorTor Exit NodeVPN/Proxy DetectDomain ReputationTyposquat DetectUsername SearchFavicon Hash
GitHub ActionsDockerfile Gendocker-composeArgoCD AppK8s Manifests
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Is It Down?

Check if any website is reachable right now. Probed from a Cloudflare edge server and a neutral host, so a site that only blocks Cloudflare is not reported as down.

Enter a domain or URL to check if it is reachable

Check a popular site
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Related Tools

Ping / Latency

Send real ICMP echo requests from a neutral host to any server. Runs 5 packets and reports min, avg, max, and packet loss.

HTTP Status Codes

Look up any HTTP status code or check the live status of a URL.

HTTP Timing

Measure TTFB and HTTP response time for any URL from our servers, not your browser: the total from Cloudflare’s nearest edge, each phase from our own server.

About this tool

What does this tool check?

It sends an HTTP HEAD request from a Cloudflare edge server to the target URL and reports back the HTTP status code and response time. A 2xx or 3xx response means the server is up and reachable. A 5xx response means the server returned an error. No response at all (timeout) means the host could not be reached from the edge server.

For popular services like GitHub, Discord, Cloudflare, OpenAI, Anthropic, Vercel, GitLab, Stripe, npm, Reddit, Atlassian, Slack, Figma, and others, the tool also pulls the official status from their status page API. A colored dot on each site card shows the current status at a glance: green means all systems operational, amber means a degraded service, orange or red means a partial or major outage. This catches cases where a site returns HTTP 200 but is functionally broken, like a Cloudflare outage where the HTML loads but JavaScript crashes.

How is this different from Ping?

The Ping tool measures latency over 5 rounds and shows min, avg, and max response times - it is focused on how fast a host responds. This tool asks a single question: is it up right now? One check, clear UP / DOWN verdict, HTTP status code shown.

What does a 4xx response mean?

A 4xx status (400 Bad Request, 403 Forbidden, 404 Not Found, etc.) means the server responded and is reachable - but rejected the request. This often happens because the site geo-blocks Cloudflare IPs, requires authentication, or blocks HEAD requests. The site itself is almost certainly up; the result is shown in amber to flag that the response was not a clean success.

Why might the result differ from what I see locally?

This check runs from the Cloudflare edge node nearest to you and from our own server. Our server keeps the address you checked (without anything after a '?') for a year, to show its history. If the site shows DOWN but you can reach it in your browser, the most likely explanations are: (1) the site blocks Cloudflare's IP ranges, (2) there is a regional outage affecting only some locations, or (3) the site requires a browser-like TLS fingerprint and rejects automated requests. If the site shows UP but you cannot reach it, your local network or ISP is the more likely culprit.