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Down Checker
Is the site down for everyone or just you? Find out in seconds, with the reason.
Free, no sign-up. Scan only sites you own or may test. 60 scans an hour per address.
When a site will not load, the first question is whether it is you or them. This checker asks the site from our own probe, walks every step a browser takes (DNS, the connection, the secure handshake, the server's answer) and tells you which one failed and what that usually means, instead of a bare up or down.
Check any site from your bookmarks bar
Drag this button to your bookmarks bar. On a page that will not load properly, click it to check that site here.
What it checks.
The cause in one sentence
We walk DNS, the connection, the TLS handshake and the HTTP answer, and name the first step that failed, so "down" comes with a reason.
Errors decoded
500, 502, 503, 504 and Cloudflare's 520 to 530 each mean something different (often: the server behind the CDN is down, not the CDN). We say which.
Up, gated or down
A Cloudflare, Sucuri, Imperva or AWS WAF challenge is reported as "up but gated", never as down: the edge is working, it just stopped our robot.
Retry before saying down
We try the other form of the address too (www or not, http or https) at the same time, so one bad redirect or one slow first connection does not read as an outage.
Edge versus origin
When a CDN answers from its cache we say so: a cached copy can stay up while the server behind it is down.
Evidence you can share
Every check has a timestamped link with every probe's raw result, to send to your host, your ISP or a client.
Methodology.
Verdict v1.0. One probe in AWS US East requests the address, following redirects one by one, and at the same time tries the other forms of it (www or not; http or https). The verdict is Up for a normal answer (a 4xx is up, with the status named), Gated when a firewall or bot challenge answered, Error for a 5xx, and Down when no HTTP answer came at all. If the address fails but another form of it answers, the site is reported up, with the first failure as a finding.
At the same time the name is asked of three public resolvers (Cloudflare 1.1.1.1, Google 8.8.8.8 and AdGuard DNS) over DNS over HTTPS. When validating resolvers answer SERVFAIL but answer with DNSSEC checking switched off, DNSSEC is broken: most visitors cannot reach the site even when our probe can. Some resolvers not finding the name, or failing, is reported too; different addresses from each are normal for a CDN.
What each failure means
| dns-nxdomain | The domain does not exist in DNS | DNS answered NXDOMAIN: there is no such name. The domain may have expired, been typed wrong, or lost its DNS records. |
| dns-no-address | The domain has no address record | The name exists but has no A or AAAA record, so browsers have nowhere to connect. |
| dns-timeout | DNS did not answer in time | The domain's nameservers did not answer within 5 seconds, or answered with a temporary failure. |
| connect-refused | The server refused the connection | Something answers at that address but nothing listens on the web port (the TCP connection was reset at once). The web server is probably stopped, or listens on another port. |
| connect-timeout | The server did not accept a connection in time | No reply to the connection attempt: the server is down, overloaded, or a firewall drops the traffic. |
| connect-unreachable | No route to the server | The network could not reach that address at all (no route). |
| tls-error | The TLS (HTTPS) handshake failed | The server accepted the connection but the secure handshake did not complete: no certificate for this name, an old protocol only, or a server that closes the connection during the handshake. |
| http-timeout | The server connected but did not answer in time | The connection was made, but no complete response came back within the time limit: the application is hanging or very slow. |
| reset | The connection was reset mid-response | The server (or something in between) closed the connection before the response was complete. |
| too-many-hops | Too many redirects | The page redirects more than 10 times, which usually means a loop (for example http to https and back, or www to apex and back). |
| HTTP 500 | 500 Internal Server Error | the application crashed while building the page (a code error, a failed database call, a bad deploy). |
| HTTP 502 | 502 Bad Gateway | a proxy or load balancer in front of the site got no valid answer from the application behind it: the app is down, restarting or crashing. |
| HTTP 503 | 503 Service Unavailable | the server is refusing work for now: maintenance mode, overload, or no healthy backends. |
| HTTP 504 | 504 Gateway Timeout | a proxy waited for the application and gave up: the app is hanging or far too slow. |
| HTTP 520 | Cloudflare 520 | the origin returned an empty, unknown or unexpected answer to Cloudflare (often a crash or a reset connection on the origin). |
| HTTP 521 | Cloudflare 521: web server is down | Cloudflare reached the origin's address but the web server refused the connection: it is stopped, or a firewall blocks Cloudflare's addresses. |
| HTTP 522 | Cloudflare 522: connection timed out | Cloudflare could not open a connection to the origin in time: the server is overloaded, offline, or dropping Cloudflare's traffic. |
| HTTP 523 | Cloudflare 523: origin is unreachable | Cloudflare cannot route to the origin at all: the DNS record points at a wrong or dead address. |
| HTTP 524 | Cloudflare 524: a timeout occurred | Cloudflare connected to the origin, but the application took longer than 100 seconds to answer. |
| HTTP 525 | Cloudflare 525: SSL handshake failed | Cloudflare could not complete TLS with the origin: no certificate or a TLS setting mismatch on the origin. |
| HTTP 526 | Cloudflare 526: invalid SSL certificate | In Full (strict) mode, the origin's certificate is expired, self-signed or for another name. |
| HTTP 530 | Cloudflare 530 | Cloudflare could not resolve or reach the origin (shown with a 1xxx error such as 1016, origin DNS error). |
Timeouts: 10 seconds per request and 25 seconds in all for the address, 8 and 12 seconds for the retries; DNS 5 seconds.
Error codes explainedPopular servicesInternet weatherMethodology changelog
Free JSON API.
No key needed: 60 requests an hour per address. Every answer carries X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset, and a 429 carries Retry-After. The same URL asked again within a minute returns the same scan. Tool id: down. Add ®ions=all to ask every region. Status badge: /api/tools/v1/badge/down?url=example.com. Plain text for assistants and scripts: add &format=text to a check or to /api/tools/v1/result/<id>.
curl "https://bcdrpulse.com/api/tools/v1/down?url=example.com"
The answer is { id, tool, createdAt, cached, report, capture, share }: report holds the grade, findings and fixes; capture the raw probe data (every hop and header, without bodies); share the result page. A saved result: GET /api/tools/v1/result/<id>. Errors: 400 bad address, 401 a sign-up is needed, 403 an address we never scan (private or internal), 429 over the limit, 503 scanner busy. The API page has keys, badges and alerts.
Questions.
Is it down for everyone or just me?
If our probe gets a normal answer, the site is up for us, so the problem is most likely between you and the site: your network, DNS cache, VPN, browser extension or ISP. The result page lists the quick checks. If our probe fails too, it is down for more than just you.
What does "up but gated" mean?
A firewall or bot-protection service (Cloudflare, Sucuri, Imperva, AWS WAF, Wordfence and others) answered our scanner with a challenge or block page. The site's edge is working; people with a normal browser usually get through. A robot cannot prove the page works for humans, so we say gated rather than guess.
What do Cloudflare 521, 522 and 524 mean?
They come from Cloudflare but describe your origin server: 521 the web server refused Cloudflare's connection, 522 it did not accept a connection in time, 524 it connected but did not answer within 100 seconds. Fix the server behind Cloudflare, not Cloudflare.
Do you check from several countries?
Yes, when you ask. Every check runs from AWS US East (N. Virginia); tick "From every region" and Europe (Ireland) and Asia Pacific (Mumbai) answer too, so a site that fails in one part of the world shows up. A site can still be blocked in a country or on an ISP we do not check from.
Can I get told when it is back?
Use "Watch this site": add it as an asset (free plan) and the monitor checks it every few minutes and alerts you by email or webhook when it goes down or comes back.
Is there an API?
Yes: GET https://bcdrpulse.com/api/tools/v1/down?url=example.com returns the verdict, the failing layer and every probe's raw result as JSON, 60 requests an hour per IP with no key.
More free checkers.
Scans come from our probe on AWS (US East by default) with the User-Agent BCDRPulseHeaders (about our scanner). We store results for 30 days so share links work, and never store page bodies. Want this checked every few minutes with alerts? Add the site as a verified asset and uptime monitoring watches it. API