HTTP
500 Internal Server Error
The server encountered an unexpected condition that prevented it from fulfilling the request. A generic catch-all for server-side errors.
When You See This Code
When an unhandled exception occurs, a database connection fails, or server code has a bug.
How to Fix
Check server logs for the stack trace. Common causes: unhandled exceptions, database errors, misconfigurations.
Specification
View RFC / Specification →Related Codes
Cross-Protocol Equivalents
Comparisons
Guides
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HTTP Fundamentals
HTTP Redirects: 301 vs 302 vs 307 vs 308
HTTP Fundamentals
HTTP Caching: Cache-Control, ETags, and 304 Responses
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Choosing the Right HTTP Status Codes for REST APIs
API Design
gRPC Status Codes: A Practical Guide
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Debugging 502 Bad Gateway Errors
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Debugging CORS Errors: A Developer's Guide
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Debugging Timeout Errors: 408 and 504
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401 Unauthorized vs 403 Forbidden: When to Use Each
Security & Authentication
Essential HTTP Security Headers
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Complete Guide to HTTP Methods: GET, POST, PUT, PATCH, DELETE
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HTTP/2 vs HTTP/3: What Changed and Why
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How to Implement and Handle Rate Limiting (429)
API Design
API Versioning Strategies: URL, Header, and Query Param
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Designing Consistent API Error Responses
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Debugging 503 Service Unavailable Errors in Production
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TLS/SSL Certificate Troubleshooting Guide
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OAuth 2.0 Flows Explained: Authorization Code, Client Credentials, PKCE
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JSON Web Tokens: Structure, Signing, and Common Pitfalls
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API Keys vs OAuth vs JWT: Choosing the Right Auth Method
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