HTTP Status Codes
Every HTTP status code, explained in plain English. Click any code for the full meaning, what to do when you see it, and how long it usually takes to resolve.
Looking for a status message that is not an HTTP code? Use the Status Meaning Decoder →
How to test what a real site is returning
If you are seeing one of these codes on a specific website, the StatusDetector Website Down Checker probes the URL from our servers and reports the actual HTTP status, DNS resolution, SSL certificate, and response latency.
Open the Website Down CheckerFrequently asked
What is an HTTP status code?
An HTTP status code is a three-digit number returned by a web server in response to a request. It tells you whether the request succeeded (2xx), was redirected (3xx), failed because of the request (4xx), or failed because of the server (5xx).
What is the difference between a 4xx and a 5xx error?
A 4xx error means the request itself was the problem — bad URL, missing credentials, or asking for something that does not exist. A 5xx error means the server received your request but failed to handle it. 4xx is on you (or your client); 5xx is on them.
Why am I seeing the same error on multiple sites?
If you see network-level errors (like ERR_CONNECTION_REFUSED or NXDOMAIN) on multiple sites at once, the problem is probably your network or DNS. If you see a 5xx code from many sites that all share infrastructure (like Cloudflare), it is more likely an upstream provider outage.