HTTP Status Codes & Header Inspector
Search offline HTTP 1xx–5xx status definitions with RFC links and inspect raw headers with automatic credential masking.
Raw HTTP Header Inspector (100% Offline · Zero Outbound Requests)
Authorization, Cookie, Set-Cookie, X-Api-Key) are automatically masked by default until explicitly revealed locally.| Header | Value | Category / Notes |
|---|---|---|
| Location | https://draftsbook.test/dashboard | redirectRedirect target URI |
| Cache-Control | public, max-age=300, stale-while-revalidate=60 | cacheCache directives: public, max-age=300, stale-while-revalidate=60 |
| Content-Type | application/json; charset=utf-8 | contentMedia type & encoding |
| ETag | "a1b2c3d4" | cacheStrong ETag validator |
| Vary | Accept-Encoding | cache |
| Vary | Origin | cache |
| Set-Cookie | •••••••• (masked credential value, 60 chars) | credentialCredential masked by default |
| Set-Cookie | •••••••• (masked credential value, 17 chars) | credentialCredential masked by default |
| Authorization | •••••••• (masked credential value, 29 chars) | credentialCredential masked by default |
HTTP Status Code Catalog (1xx–5xx · 32 shown)
Initial request headers received; client should send the remaining body.
Cache behavior: Not cacheable
Server agrees to upgrade connection protocol (e.g., to WebSocket).
Cache behavior: Not cacheable
Request succeeded; representation is included for GET/POST responses.
Cache behavior: Cacheable by default when explicit freshness headers allow
Request succeeded and created a new resource (typically referenced via Location).
Cache behavior: Not cacheable unless explicit freshness provided
Request accepted for asynchronous background processing.
Cache behavior: Not cacheable
Request succeeded with intentionally empty message body.
Cache behavior: Cacheable if headers permit
Partial byte-range payload returned matching a Range request.
Cache behavior: Cacheable with Content-Range / ETag validation
Target URI moved permanently to Location (browsers may change POST to GET).
Cache behavior: Cacheable by default
Temporary redirect to Location (method often rewrites POST to GET; prefer 307/303).
Cache behavior: Requires explicit Cache-Control / Expires
Redirect after POST/PUT so client retrieves result via GET at Location.
Cache behavior: Only with explicit freshness directives
Conditional request matched cached ETag / Last-Modified; reuse local copy.
Cache behavior: Validates cached entry without resending body
Temporary redirect preserving original HTTP method and body.
Cache behavior: Requires explicit freshness directives
Permanent redirect preserving original HTTP method and body.
Cache behavior: Cacheable by default
Malformed syntax, invalid parameters, or failed request framing.
Cache behavior: Not cacheable
Missing or invalid authentication credentials (expect WWW-Authenticate).
Cache behavior: Not cacheable by shared caches
Server understood request, but caller lacks authorization permissions.
Cache behavior: Only if explicit freshness given
Origin server did not find a current representation at the target URI.
Cache behavior: Cacheable if explicit freshness allows
HTTP verb not supported on target URI (check Allow response header).
Cache behavior: Cacheable with explicit freshness
Request conflicts with current target resource state (e.g., optimistic lock mismatch).
Cache behavior: Not cacheable
Resource permanently deleted with no forwarding URI known.
Cache behavior: Cacheable by default
Conditional request headers (If-Match / If-Unmodified-Since) failed.
Cache behavior: Not cacheable
Request payload exceeds server-configured body limit.
Cache behavior: Not cacheable
Request Content-Type or Content-Encoding is unsupported by endpoint.
Cache behavior: Not cacheable
Request JSON/syntax is valid, but semantic validation failed.
Cache behavior: Not cacheable
Client exceeded rate limit threshold; check Retry-After header.
Cache behavior: Not cacheable
Access denied as a consequence of legal demand.
Cache behavior: Cacheable if explicit freshness permits
Server encountered an unexpected condition preventing request completion.
Cache behavior: Only cached with explicit directives
Server does not support the functionality required to fulfill request.
Cache behavior: Cacheable by default when explicit
Reverse proxy or gateway received an invalid response from upstream.
Cache behavior: Do not cache transiently unless configured
Server overloaded or in maintenance; check Retry-After header.
Cache behavior: Not cacheable
Gateway did not receive a timely response from the upstream server.
Cache behavior: Not cacheable
Captive portal or proxy requires network-level authentication first.
Cache behavior: Not cacheable