The Universal Status Code Encyclopedia
Comprehensive reference for HTTP, SMTP, gRPC, DNS, WebSocket, FTP, and SIP status codes — with examples, comparisons, and interactive tools.
The foundation of data communication on the web. HTTP status codes indicate the result of a client's request to a …
The standard protocol for sending email across the Internet. SMTP reply codes indicate the success or failure of mail transactions.
A high-performance RPC framework by Google. gRPC status codes describe the outcome of remote procedure calls.
The hierarchical naming system for computers and services on the Internet. DNS response codes (RCODEs) indicate query results.
A protocol providing full-duplex communication channels over a single TCP connection. Close codes indicate why a connection was terminated.
A standard protocol for transferring files between a client and server. FTP reply codes indicate the status of file transfer …
A signaling protocol for initiating, maintaining, and terminating multimedia sessions. SIP response codes follow a structure similar to HTTP.