Error map
The page isn’t redirecting properly Firefox: The page isn’t redirecting properly — Firefox has detected that the server is redirecting the request in a way that will never complete
Browser · layer 1, On your device
Centre: this error. First ring: errors it is linked with (10). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (10)
HTTP 302 Found (Temporary Redirect)
The resource is temporarily at another URL; clients should keep using the original URL for future requests.
ERR_TOO_MANY_REDIRECTS with Cloudflare (Flexible SSL redirect loop)
The page redirects to itself forever — classic cause: Cloudflare SSL mode “Flexible” while the origin redirects HTTP to HTTPS.
HTTP 303 See Other
A redirect telling the client to fetch the result from another URL with GET — used after a form POST so refreshing doesn’t resubm…
HTTP 307 Temporary Redirect
A temporary redirect that keeps the original method and body — a POST stays a POST at the new URL.
HTTP 301 Moved Permanently
The resource has a new permanent URL; clients and search engines should use the address in the Location header from now on.
HTTP 308 Permanent Redirect
A permanent redirect that, unlike 301, guarantees the method and body are kept.
Chrome: This page isn’t working — example.com redirected you too many times. ERR_TOO_MANY_REDIRECTS
The page keeps redirecting to itself or in a loop, so the browser gives up after about 20 redirects.
Firefox: Warning: Potential Security Risk Ahead — SEC_ERROR_UNKNOWN_ISSUER (certificate not trusted)
Firefox does not trust the authority that issued the site's certificate — a self-signed certificate, a missing intermediate, or a…
Firefox: Secure Connection Failed — SSL_ERROR_NO_CYPHER_OVERLAP (no common cipher)
Firefox and the server share no TLS cipher suite, so the secure handshake cannot even start.
Firefox: Hmm. We’re having trouble finding that site. / Server not found (DNS_PROBE or NS_ERROR_UNKNOWN_HOST)
Firefox could not resolve the website’s hostname to an IP address — a typo, a DNS problem or no internet.
Two steps away (27)
HTTP 401 Unauthorized
The request has no valid authentication credentials — you need to log in or send a valid token.
SyntaxError: Unexpected token < in JSON at position 0
`JSON.parse()` / `response.json()` received something that isn’t JSON — very often an HTML error page.
HTTP 200 OK (but something is still wrong)
The request succeeded at the HTTP level — yet the page is blank, the data is wrong, or an error is hidden inside the response bod…
Cloudflare Error 525: SSL Handshake Failed
Cloudflare couldn’t complete a TLS handshake with your origin (SSL mode Full / Full strict).
ERR_SSL_VERSION_OR_CIPHER_MISMATCH on a Cloudflare site (certificate not issued / multi-level subdomain)
Cloudflare has no edge certificate for the hostname — the Universal SSL cert is still pending, or the hostname is a second-level…
NET::ERR_CERT_AUTHORITY_INVALID with a Cloudflare Origin Certificate (record not proxied)
Cloudflare Origin CA certificates are only trusted by Cloudflare — visitors reaching the origin directly (grey-cloud record, dire…
HTTP 100 Continue
An interim response telling the client to go ahead and send the request body — normal when the client sent Expect: 100-continue.
HTTP 103 Early Hints
An interim response that sends Link headers early so the browser can preload CSS, fonts or scripts while the server is still buil…
WordPress: ERR_TOO_MANY_REDIRECTS / redirected you too many times on wp-admin or the whole site
WordPress and the server/proxy keep redirecting to each other — usually siteurl/home mismatch (http vs https, www vs non-www) or…
Mixed Content: The page was loaded over HTTPS, but requested an insecure resource
An HTTPS page tried to load a script, API or image over plain HTTP, and the browser blocked (or warned about) it.
CLEARTEXT communication to host not permitted by network security policy
Android 9+ blocks plain `http://` requests by default; the app tried to call a non-HTTPS URL.
App Transport Security has blocked a cleartext HTTP resource load
iOS blocked an `http://` request (or a weak-TLS HTTPS one) because App Transport Security requires secure connections.
HTTP 404 Not Found
The server can’t find anything at the requested URL.
HTTP 410 Gone
The resource used to exist but was intentionally and permanently removed, with no forwarding address.
Cloudflare Error 520: Web Server Returned an Unknown Error
Cloudflare connected to your origin, but the origin returned an empty, unknown or invalid response.
Chrome: This page isn’t working — example.com didn’t send any data. ERR_EMPTY_RESPONSE
The server accepted the connection but closed it without sending any HTTP response — a crash, timeout or misconfigured proxy on t…
Chrome: This page isn’t working — example.com is unable to handle this request. ERR_HTTP2_PROTOCOL_ERROR
The HTTP/2 connection broke a protocol rule — a server, proxy or CDN sent an invalid or oversized frame/header, or closed the str…
Chrome DevTools: net::ERR_CONTENT_LENGTH_MISMATCH — body shorter than the Content-Length header
The server promised a number of bytes in `Content-Length` and sent a different number, so Chrome treats the download as corrupted.
NET::ERR_CERT_AUTHORITY_INVALID (Your connection is not private)
The site’s certificate isn’t signed by a CA the browser trusts — self-signed, missing intermediates, or intercepted by a proxy.
Let’s Encrypt / Certbot: Challenge failed for domain example.com — Invalid response from http://example.com/.well-known/acme-challenge/x: 404
Let’s Encrypt couldn’t verify you control the domain — the HTTP-01 challenge file wasn’t served, or DNS points elsewhere.
NET::ERR_CERT_COMMON_NAME_INVALID: Your connection is not private (certificate is for a different domain)
The certificate presented doesn’t include the hostname you visited — e.g. visiting www.example.com with a certificate only for ex…
ERR_SSL_PROTOCOL_ERROR (This site can't provide a secure connection)
The browser couldn’t negotiate TLS — the server sent an invalid response, often plain HTTP on the HTTPS port.
Chrome: This site can’t be reached — example.com unexpectedly closed the connection. ERR_CONNECTION_CLOSED
The server closed the connection before finishing the TLS handshake or sending a response — typical for HTTP/HTTPS port mix-ups,…
Chrome: This site can’t provide a secure connection — uses an unsupported protocol. ERR_SSL_VERSION_OR_CIPHER_MISMATCH
The browser and the server could not agree on a TLS version or cipher — the server is too old or misconfigured, or the browser is.
net::ERR_NAME_NOT_RESOLVED (This site can't be reached — server IP address could not be found)
DNS couldn’t resolve the hostname in the browser.
Cloudflare Error 523: Origin is unreachable
Cloudflare can’t find a network route to your origin server — the DNS record points to a wrong/unroutable IP or the origin networ…
Cloudflare HTTP 530 (with Error 1016 Origin DNS error / 1033 tunnel error)
Cloudflare returns 530 together with a 1xxx error; the 1xxx code (usually 1016 or 1033) tells you the real cause.
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