HTTP Status Codes Lookup Online

Search and browse HTTP status codes with descriptions, categories, and usage examples.

💡

Quick Answer

An HTTP status codes lookup online lets you search all standard HTTP response codes (1xx–5xx) by number or keyword. Learn what 404, 500, 401, and other codes mean with full descriptions and usage context.

What are HTTP Status Codes?

HTTP status codes are standardised three-digit response codes returned by web servers to indicate the result of a client request. They are defined in RFC 7231 and grouped into five classes. Every API response, page load, and redirect carries a status code that tells the client whether the request succeeded, failed, or requires further action.

Also try our JSON Formatter, Regex Tester, and URL Encoder.

1xx

Informational

Request received, processing continues.

2xx

Success

Request was received and accepted.

3xx

Redirection

Further action needed to complete request.

4xx

Client Error

Bad request or resource not found.

5xx

Server Error

Server failed to fulfil the request.

What is an HTTP Status Codes Lookup Online?

An HTTP status codes lookup online is a browser-based reference tool that lets you search all standard HTTP response codes by number or keyword. Developers use it during API development, debugging, and backend implementation to quickly identify what 404, 500, 401, 422, and other codes mean — including their RFC definitions and usage context.

Commonly Referenced Codes

200OK

Request succeeded. Standard success response for GET and POST.

201Created

Resource created successfully. Returned after a successful POST.

301Moved Permanently

Resource has permanently moved to a new URL.

400Bad Request

Server could not understand the request due to invalid syntax.

401Unauthorized

Authentication is required and has failed or not been provided.

403Forbidden

Server understood the request but refuses to authorise it.

404Not Found

The requested resource could not be found on the server.

429Too Many Requests

Rate limit exceeded. Slow down and retry after the cooldown period.

500Internal Server Error

Generic server error with no more specific message available.

Key Features

✓Search by code or keyword — Type a code like 404 or a phrase like "not found" to filter results

✓Category filter tabs — Filter codes by class: 1xx, 2xx, 3xx, 4xx, or 5xx

✓Detailed descriptions — Each code includes a full description with RFC reference and usage guidance

✓Expandable cards — Click any code to expand its full detail panel inline

✓All 60+ codes covered — Includes all standard HTTP/1.1 and common extension codes

✓100% client-side — No API calls — the entire reference is embedded and instant

Common Use Cases

API Development

Verify which status codes to return for different outcomes: 201 for creation, 422 for validation errors, 429 for rate limiting.

Debugging

Quickly look up an unfamiliar code received from an external API or service during development.

Backend Development

Reference the correct code when implementing error handling, authentication guards, and redirect logic.

Testing & QA

Confirm expected response codes in automated tests and integration test suites.

Learning HTTP

Understand how web communication works by exploring each status code category and its semantics.

Client Error Handling

Build better frontend error messages by understanding what each 4xx response actually means.

Why Use This Tool

→Instant lookup: No need to open MDN or RFC documents mid-debugging — search and find in seconds.
→Full coverage: Includes informational, success, redirect, client error, and server error classes.
→RFC references: Each entry links to its defining RFC so you can read the authoritative specification.
→No API calls: The entire database is embedded — works offline and responds instantly.
→Category filtering: Narrow down to 4xx or 5xx codes when diagnosing client or server errors.
→Free forever: No account, no subscription — open and search any time.

Frequently Asked Questions

What is an HTTP status codes lookup online?

An HTTP status codes lookup online is a browser-based reference tool for searching all standard HTTP response codes (1xx–5xx) by number or keyword. Codes are grouped into informational (1xx), success (2xx), redirection (3xx), client error (4xx), and server error (5xx) categories.

What does a 404 error mean?

A 404 Not Found response means the server could not find the requested resource. It is commonly caused by broken links, deleted pages, or incorrect URLs.

What is a 500 error?

A 500 Internal Server Error indicates that the server encountered an unexpected condition that prevented it from fulfilling the request. It is a generic catch-all for unhandled server-side exceptions.

Can I search by description?

Yes. Type a keyword like "not found", "redirect", or "unauthorized" into the search bar and matching codes will appear instantly.

Is this HTTP status codes tool free?

Yes. The HTTP Status Codes Lookup on NexoraTools is completely free with no sign-up or restrictions.

Cron Expression ExplainerParse, explain, and build cron expressions visually.

Regex TesterTest regular expressions with live match highlighting.