HTTP Status Code Explorer

Pick a code from the list or search by digits to see meaning, typical situations, and debugging guidance. Filter by 1xx–5xx families.

Report

Select a status code on the left, or type digits to narrow the list.

Step 1

Use the family chips (1xx–5xx) to narrow the list, or type digits (e.g. “40” lists 400–499).

Step 2

Click any row on the left; the right panel shows meaning, situations, and tips.

Step 3

Map the guidance to your stack (proxy, gateway, framework) and check whether errors rewrite status codes or bodies.

When would I use this HTTP status code explorer?

Whenever you see a code while debugging APIs, redirects, login flows, or CDN caching—304, 409, 502, etc.—and want a quick reminder of what it means, where issues usually hide, and what to inspect next.

How do status codes relate to JSON error bodies?

The status summarizes the overall outcome; the real reason is often in the body (e.g. JSON message/code) or headers (WWW-Authenticate, Location, Retry-After). Read both together.

Why does my code differ from the API docs?

Intermediaries may rewrite codes (e.g. surface 502 instead of upstream 500, or normalize auth failures to 401/403). Trace the full request path: proxy, gateway, load balancer, and app logs.

What is the main difference between 4xx and 5xx?

4xx usually means the request or client-visible state can be corrected (bad input, authz, missing resource). 5xx usually means the server or upstream failed or is temporarily unable to handle the request—still verify with the specific code and payload.

Does this tool upload my URL or tokens?

No. Reference text ships with the page; filtering runs locally in your browser. URLs, tokens, and API payloads are not sent to this tool.

API REST HTTP

2026-06-22

API Resource State Management: From HTTP Semantics to Consistent Architecture

A deep dive into the philosophy of resource management behind HTTP status codes, exploring state consistency, idempotency, and common API design pitfalls in RESTful architectures.

API HTTP Web Development

2026-06-02

Optimizing Network Communication: Advanced Practices for High-Performance API Construction

Deep dive into modern Web API communication architectures, from precise status code application to protocol fine-tuning, to improve system stability and developer experience.

regular expression regex form validation

2026-04-22

Regex Patterns Cheat Sheet: Email, Phone, Date Validation & More

Learned regex syntax but not sure how to apply it? This guide compiles 10 essential validation patterns used by developers every day — from email and phone numbers to URLs, IP addresses, and password strength rules. Each pattern comes with detailed explanations, edge cases, and ready-to-use code.

encoding Unicode URL-encoding

2026-06-03

Encoding Standards and Network Transmission: A Complete Guide to Character and URL Encoding

Understand the mechanics of character encoding, Base64 applications, and the vital role of URL encoding in modern web communication to resolve encoding issues.

ISO 8601 Date Format Timezone Handling

2026-05-26

ISO 8601 Date Standard: The Universal Language of Data Exchange

Dive deep into the ISO 8601 date format and learn how standardized time formats can solve challenges in cross-timezone and cross-system data transmission and parsing.

Encoding Standards UTF-8 URL Encoding

2026-05-24

Character Encoding and URL Safety: A Practical Guide from UTF-8 to Percent-Encoding

A deep dive into how computers process text encoding, exploring URL encoding rules and the critical impact of character conversion on system stability.