Developer error reference

Error codes.
Explained. Fixed.

One reference for every error code you'll ever hit. Real causes. Working fixes. No noise.

$ lookup
⌘K
7,377+
// error codes indexed
21 lang
// languages & platforms
100%
// with working fixes
Database
6
errcodes.dev — lookup
$ GET /postgresql/23505
// unique_violation
code: "23505"
class: "Integrity Constraint Violation"
cause: "duplicate key value violates unique constraint"
fix: "INSERT ... ON CONFLICT DO UPDATE SET ..."
cross-ref: MySQL 1062 · SQLite SQLITE_CONSTRAINT_UNIQUE
Runtime & Web
11
System & DevOps
4

About This Reference

errcodes.dev is a comprehensive error code reference covering 21 languages and platforms. Every entry includes the exact cause, a working fix with code examples, and cross-references to the same error in other languages.

Database errors covered include PostgreSQL SQLSTATE codes, SQLite result codes, MySQL error numbers, and MariaDB error codes. NoSQL developers will find MongoDB error codes and Redis RESP error replies.

Systems and DevOps errors include Linux/POSIX errno codes (ENOENT, EACCES, ECONNREFUSED), Docker exit codes, and Kubernetes pod states like CrashLoopBackOff and OOMKilled.

Runtime errors include Python exceptions, Node.js error codes, TypeScript diagnostic codes, and Bash exit codes. API and network errors include HTTP status codes, gRPC status codes, and SMTP response codes.