Free online bulk lookup for HTTP status codes: paste many codes or import a .txt file to get names, classes, meanings and troubleshooting notes in one pass
One code per line, or mixed separators (commas, semicolons, spaces) - or import a log or text file directly
Each entry shows the code, its name and a colour-coded class badge from 1xx to 5xx
Frequent errors such as 301/302/304/404/429/500/502/503/504 come with practical debugging pointers
Totals for entries, recognised, unknown and malformed codes plus a per-class count
Optionally deduplicate, sort numerically, or show only one class such as 5xx
Everything is parsed in your browser - nothing is uploaded and no account is needed
Copy status codes from logs, API responses or test notes into the box, or use "Import txt file" to load a text file automatically.
Enable deduplication or sorting as needed, and use "Filter class" (4xx, 5xx, ...) to focus on the errors you care about.
Click Batch Check: the table lists each code with its name, class badge and meaning/troubleshooting notes; unknown or malformed entries are flagged too.
The statistics row shows entries, recognised, unknown, malformed and the class breakdown; use Copy Result to paste the digest into a ticket or document.
Paste every code seen during integration to tell at a glance whether the request or the server is at fault
Extract the status column from Nginx, gateway or application logs and interpret plus count 4xx/5xx share in bulk
When an alert contains several codes, look them up together with notes to speed up triage
301, 302, 404 and 410 in crawl logs affect indexing - check their meaning and intended use in bulk
Check a full set of codes at once and study how the 1xx-5xx hierarchy is organised
Review your API test matrix to confirm you cover edge cases like 401, 403, 409, 415 and 429
An HTTP status code is a three-digit number whose first digit signals the class: 1xx informational (request received and being processed, e.g. 100, 101); 2xx success (200, 201, 204, 206); 3xx redirect (301, 302, 304); 4xx client error (400, 401, 403, 404); 5xx server error (500, 502, 503, 504). Remembering the first digit instantly tells you who is responsible.
400 Bad Request usually means malformed parameters or body; 401 Unauthorized means missing or expired credentials; 403 Forbidden means authenticated but not permitted; 404 Not Found means the path or resource does not exist; 405 Method Not Allowed means the method is unsupported for that resource; 429 Too Many Requests means rate limiting. Check parameters, auth headers, path spelling and call frequency first.
301 and 308 are permanent redirects: 301 allows clients to change POST to GET, while 308 preserves the original method. 302 and 307 are temporary: 302 may also change the method, whereas 307 strictly preserves method and body. For form submissions and API redirects prefer 307/308 so the request body is not lost.
500 Internal Server Error points at an application exception - start with logs and stack traces. 501 means the server does not support the functionality. 502 Bad Gateway means the proxy got an invalid upstream response, often a crashed backend or closed port. 503 Service Unavailable usually means overload, rate limiting or maintenance. 504 Gateway Timeout means the upstream was too slow. Typical order: verify backend health and latency, then gateway and timeout settings, then network and dependencies.
| Code | Name | Summary |
|---|---|---|
| 200 | OK | Request succeeded with expected content |
| 201 | Created | Resource created (typically after POST) |
| 204 | No Content | Succeeded with no body (often DELETE) |
| 206 | Partial Content | Partial response for ranged requests |
| 301 | Moved Permanently | Permanent move, update links |
| 302 | Found | Temporary redirect that may change |
| 304 | Not Modified | Cache still valid, reuse local copy |
| 307 | Temporary Redirect | Temporary redirect preserving method |
| 308 | Permanent Redirect | Permanent redirect preserving method |
| 400 | Bad Request | Malformed syntax or parameters |
| 401 | Unauthorized | Missing or expired credentials |
| 403 | Forbidden | Authenticated but not allowed |
| 404 | Not Found | Resource missing or path mistyped |
| 405 | Method Not Allowed | Method unsupported for the resource |
| 408 | Request Timeout | Client sent the request too slowly |
| 410 | Gone | Resource permanently removed |
| 413 | Payload Too Large | Body exceeded the allowed size |
| 415 | Unsupported Media Type | Content-Type not supported |
| 418 | I am a teapot | April Fools code from RFC 2324 |
| 422 | Unprocessable Content | Semantic validation failed |
| 429 | Too Many Requests | Rate limited, slow down |
| 451 | Unavailable For Legal Reasons | Blocked for legal reasons |
| 500 | Internal Server Error | Server-side exception |
| 502 | Bad Gateway | Invalid response from upstream |
| 503 | Service Unavailable | Overloaded or under maintenance |
| 504 | Gateway Timeout | Upstream timed out |