HTTP Status Code Lookup
Quickly search, browse, understand, and compare HTTP response status codes. Includes framework code snippets (Laravel, Express, Next.js, Spring Boot, ASP.NET), caching rules, and SEO impact.
Continue
Initial request headers received; client should proceed to send request body.
Switching Protocols
Server agrees to switch application protocol (e.g. HTTP/1.1 to WebSockets).
Early Hints
Allows server to return Link headers before final HTTP response is ready to preload assets.
OK
Request succeeded. The payload sent depends on the HTTP method used.
Created
Request succeeded and a new resource was created as a result.
Accepted
Request has been accepted for processing, but processing has not been completed.
No Content
Request succeeded, but server is not returning any content in response body.
Partial Content
Server is delivering only part of resource due to Range header sent by client.
Moved Permanently
The target resource has been assigned a new permanent URI.
Found
The target resource resides temporarily under a different URI.
Not Modified
Resource has not been modified since last request; use cached version.
Temporary Redirect
Target resource resides temporarily under a different URI; HTTP method must not change.
Permanent Redirect
Target resource has been assigned a new permanent URI; HTTP method must not change.
Bad Request
Server cannot process request due to perceived client error (malformed syntax or payload).
Unauthorized
Request requires user authentication; credentials missing or invalid.
Forbidden
Server understands request but refuses to authorize it (insufficient permissions).
Not Found
Server cannot find the requested resource URL.
Method Not Allowed
The HTTP request method is known by server but not supported by target resource.
Request Timeout
Server timed out waiting for the client request to complete.
Conflict
Request could not be completed due to a conflict with current state of resource.
Gone
Target resource is permanently deleted and will not be available again.
I'm a teapot
April Fools joke RFC status code: Server refuses to brew coffee because it is a teapot.
Page Expired
CSRF token missing or expired (Laravel Framework Extension Code).
Unprocessable Content
Server understands content type and syntax, but request contains semantic validation errors.
Too Many Requests
The user has sent too many requests in a given amount of time (rate limited).
Unavailable For Legal Reasons
Server refuses to serve content due to legal demand or court order (named after Fahrenheit 451).
Client Closed Request
Client closed the TCP connection while Nginx was processing request.
Internal Server Error
Server encountered an unexpected condition that prevented it from fulfilling request.
Bad Gateway
Server, while acting as a gateway or proxy, received an invalid response from upstream server.
Service Unavailable
Server is currently unable to handle request due to temporary overload or maintenance.
Gateway Timeout
Server acting as gateway did not receive timely response from upstream server.
Web Server Returned an Unknown Error
Origin server returned an empty, unknown, or unexpected response to Cloudflare proxy.
Web Server Is Down
Origin web server refused TCP connection from Cloudflare reverse proxy.
Connection Timed Out
Cloudflare TCP handshake with origin web server timed out.
What is an HTTP Status Code Lookup Tool?
Overview and core technical concepts
An HTTP Status Code Lookup directory details official IANA & RFC response codes (1xx Informational, 2xx Success, 3xx Redirection, 4xx Client Error, 5xx Server Error) with root causes, fix steps, and API code snippets.
Why Lookup HTTP Status Codes?
Key advantages, developer speedups, and security benefits
Debug API Integration Failures
Understand subtle differences between `401 Unauthorized` (missing credentials) and `403 Forbidden` (insufficient permissions).
SEO Redirect Strategy
Choose correctly between `301 Permanent Redirect` (passes SEO link equity) and `302 Temporary Redirect`.
When Shouldn't You Use Documentation Only?
Anti-patterns, limitations, and when to choose an alternative approach
To execute actual live HTTP requests against a remote API server, use cURL Command Builder.
Status Code Lookup Example
Sample inputs, expected outputs, and code patterns
429 Too Many Requests
Cause: Client exceeded rate limits | Fix: Implement exponential backoff retry algorithms.Common HTTP Status Mistakes
Frequent errors, security risks, and how to fix them
Frequently Asked Questions
HTTP status codes are standardized 3-digit numerical responses returned by web servers when a client (such as a web browser or mobile app) issues an HTTP request. They inform the client whether the request succeeded, requires a redirect, failed due to client error, or encountered a server crash.
HTTP status codes are divided into 5 distinct categories based on their first digit: 1xx Informational (request received), 2xx Success (action fulfilled), 3xx Redirection (further action needed), 4xx Client Error (bad request syntax or unauthorized), and 5xx Server Error (backend crash or gateway failure).
401 Unauthorized means the user is not authenticated—they are missing credentials (or their token expired) and must log in. 403 Forbidden means the user is authenticated, but their account role lacks permission to access that specific resource.
A 301 Moved Permanently redirect signals to search engine crawlers that a URL has moved forever, transferring 90-99% of link equity (ranking power) to the new destination. A 302 Found redirect indicates a temporary move, keeping the original URL indexed without transferring long-term ranking power.
No. The ToolZeno HTTP Status Code Lookup operates 100% client-side in your web browser. All search matching, status filtering, multi-framework code snippet generation, and comparisons execute locally in browser memory without sending data to any server.
Related Tools
Password Generator
Generate highly secure, custom passwords in bulk with estimated entropy analysis and complexity metrics.
Passphrase Generator
Generate highly secure random passphrases in bulk using Diceware, BIP-39 lists, and custom rules.
Secure Token Generator
Generate cryptographically secure random tokens, JWT secrets, CSRF tokens, API keys, and symmetric encryption keys client-side.
OTP Generator
Generate cryptographically secure random OTPs, TOTP (Time-Based), and HOTP (Counter-Based) codes client-side with full parameters customization.