Error categories
Pick a technology to see its most common errors, or paste your error and let us figure it out.
HTTP
HTTP status codes from 400 Bad Request to 504 Gateway Timeout — what they mean and how to fix them on any server.
18
API
REST/GraphQL API errors: invalid tokens, CORS, rate limits, timeouts and malformed requests.
1
Authentication
Login, session, JWT and OAuth 2.0 / OpenID Connect errors.
3
JavaScript
Browser and runtime JavaScript errors: TypeError, ReferenceError, SyntaxError and promise rejections.
6
PHP
PHP fatal errors, warnings, parse errors and configuration limits.
7
Python
Python exceptions: ImportError, KeyError, TypeError, IndentationError and more.
7
Java
Java and JVM exceptions: NullPointerException, ClassNotFoundException, OutOfMemoryError.
4
SQL
Database-agnostic SQL errors: syntax, constraints, deadlocks and connection issues.
1
MySQL
MySQL and MariaDB error codes like 1045, 1064, 1146 and 2002.
9
PostgreSQL
PostgreSQL connection, authentication and query errors.
2
Git
Git and GitHub errors: rejected pushes, merge conflicts, SSH keys and unrelated histories.
5
npm
npm install and dependency errors: ERESOLVE, EACCES, lockfile and registry problems.
2
Node.js
Node.js runtime errors: module resolution, ports in use, file system and network errno codes.
4
React
React runtime and build errors: invalid children, infinite re-renders, hooks and keys.
3
Android
Android, Gradle and ADB build/install errors.
2
iOS
Xcode, Swift, CocoaPods and code-signing errors.
2
Docker
Docker daemon, image, container, port and disk errors.
3
Kubernetes
Pod states and cluster errors: CrashLoopBackOff, ImagePullBackOff, OOMKilled.
3
AWS
Amazon Web Services errors: IAM AccessDenied, expired tokens, throttling and S3 issues.
3
Azure
Microsoft Azure authentication (AADSTS) and deployment errors.
1
Linux
Linux shell, permission and package-manager errors.
2
Windows
Windows system error codes and stop codes.
Coming soon
.NET
.NET runtime and ASP.NET Core exceptions.
1
Cloudflare
Cloudflare 5xx errors (520–526) between the edge and your origin server.
4
WordPress
WordPress database, plugin, theme and server errors.
2