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Articles, guides, and insights about HTTP status codes and web development

·13 min read

Understanding HTTP 504 Gateway Timeout: Who Gave Up Waiting, and Why

What 504 Gateway Timeout really means (a proxy gave up on its upstream), how it differs from 502, 503, 408, and Cloudflare's 524, why your app usually shouldn't return it, and how to align timeouts so you stop seeing it.5xxServer Error
·12 min read

Understanding HTTP 302 Found: Temporary Redirects, the POST-to-GET Trap, and When to Use 307 Instead

What 302 Found really means, why it can silently turn POST into GET, how it differs from 301, 303, 307, and 308, and why it's the accidental default redirect in most frameworks.3xxRedirection
·11 min read

Understanding HTTP 400 Bad Request: Malformed Syntax, the 400 vs 422 Line, and When Generic Is Correct

What 400 Bad Request actually covers (syntax errors, not validation errors), how to draw the line between 400 and 422, why browsers show 400 for oversized cookies, and how to return it with an error body clients can act on.4xxClient Error
·11 min read

Understanding HTTP 403 Forbidden: Authorization, the 401 vs 403 Trap, and When to Hide a Resource Entirely

What 403 Forbidden really means (authorization, not authentication), why logging in won't fix it, how it differs from 401, 404, and 407, and how to return and handle it correctly across Express, Next.js, NGINX, and Apache.4xxClient Error
·8 min read

Understanding HTTP 308 Permanent Redirect: Method-Preserving Redirects Done Right

How 308 Permanent Redirect differs from 301, why it preserves the HTTP method, the full 301/302/303/307/308 matrix, framework gotchas (including Next.js), caching, and SEO.3xxRedirection
·9 min read

Understanding HTTP 401 Unauthorized: Authentication, WWW-Authenticate, and the 401 vs 403 Trap

What 401 Unauthorized really means (authentication, not authorization), why the WWW-Authenticate header is mandatory, when to use 401 vs 403 vs 407, and how to return and handle it correctly.4xxClient Error
·10 min read

Understanding HTTP 404 Not Found: Why It Happens and What to Do About It

The internet's most famous error explained — what 404 really means, when to use it vs. 410 or 403, how it affects SEO, and how to build a 404 page that doesn't lose users.4xxClient Error
·10 min read

Understanding HTTP 503 Service Unavailable: Planned Downtime, Overload, and Graceful Failure

A deep dive into HTTP 503 — when to return it, why Retry-After matters, how to ship maintenance windows without trashing your SEO, and the differences between 503, 500, 502, and 429.5xxServer Error
·8 min read

Understanding HTTP 103 Early Hints: Faster Pages with Smarter Preloads

How HTTP 103 Early Hints lets the server tell the browser what to preload before the real response is ready — what it does, when it helps, and how to ship it.1xxInformational
·10 min read

Understanding NGINX 499 Client Closed Request: When Your Users Give Up First

A deep dive into NGINX's 499 status code — what it means when the client hangs up before the server can respond, and how to use it as a leading indicator of problems.NGINX
·7 min read

Understanding HTTP 301 Redirects: SEO, Migrations, and Common Pitfalls

A comprehensive guide to HTTP 301 Moved Permanently — when to use it, how it affects SEO, implementation examples, and mistakes that can tank your rankings.3xxRedirection
·8 min read

Understanding 429 Too Many Requests: Rate Limiting Done Right

A deep dive into HTTP 429 Too Many Requests — why rate limiting matters, how to implement it on the server, and how to handle it gracefully as a client.4xxClient Error
·5 min read

Understanding HTTP 200 OK: The Success Status Code Explained

A comprehensive guide to the HTTP 200 OK status code — what it means, how it varies by HTTP method, common pitfalls, and best practices for API design.2xxSuccess
·7 min read

Understanding 500 Internal Server Error: Causes, Debugging, and Prevention

A deep dive into HTTP 500 Internal Server Error — what triggers it, how to debug it, and strategies to prevent unhandled server failures in production.5xxServer Error
·4 min read

Understanding 502 Bad Gateway Errors: Causes, Fixes, and Prevention

A deep dive into HTTP 502 Bad Gateway errors — what causes them, how to diagnose them, and proven strategies to prevent them in production.5xxServer Error