HTTP Status Code Lookup
Look up any HTTP status code's meaning, or browse/search the full reference table by category.
How this tool works
Search or browse
Type a code, name, or keyword, or filter by category (2xx/3xx/4xx/5xx).
See the exact meaning
A plain-language explanation of what the code means and when it's actually used.
Check commonality
Each code is tagged common, occasional, or rare so you know if it's expected or unusual.
Scan the full reference table
Every code stays visible below the search, filterable and searchable together.
Quick facts
- Category
- Text Tools
- Best for
- Understanding an unfamiliar status code in an API response, or choosing the right one to return
About this tool
Enter a status code like 404 or 503 to see its exact meaning, a plain-language explanation of when it's actually used, and whether it's something you'll commonly run into or a rare/obscure one you might not recognize - or skip the search entirely and browse the full reference table, filterable by category (2xx success, 3xx redirection, 4xx client error, 5xx server error) and searchable by code, name, or keyword. Beyond the well-known ones like 200, 404, and 500, this covers the codes that come up constantly in API and web development but are easy to mix up - the difference between 301 and 308 redirects, why 401 is about authentication while 403 is about authorization, or what 429 rate limiting actually signals to a client. Each entry is tagged by how commonly you'd actually encounter it in practice, so a genuinely obscure code like 511 isn't presented with the same weight as something you'll see in server logs every day. Useful for quickly understanding an unfamiliar status code in an API response, choosing the right code to return from your own API, or double-checking the difference between two similar-sounding codes. Runs entirely client-side against a static reference table - no live requests are made.
Why use this tool
Search and browse together
Look up a specific code instantly, or explore the full table by category without leaving the search.
Explains commonly confused pairs
Covers distinctions like 401 vs 403 or 301 vs 308 that are easy to mix up.
Commonality tagging
Flags whether a code is one you'll see constantly or a rare edge case, not just its definition.
Full category coverage
2xx success, 3xx redirection, 4xx client error, and 5xx server error codes all included.
Frequently asked questions
401 Unauthorized means authentication is missing or invalid - despite the name, it's specifically about who you are, and the correct response is to authenticate (e.g. log in). 403 Forbidden means the server knows who you are but you're not allowed to access this resource regardless - the correct response is that no amount of re-authenticating as the same user will help, since it's a permissions issue rather than an identity one.
They differ along two independent axes: permanence (301/308 signal a permanent move that clients should remember; 302/307 signal a temporary one) and method preservation (307/308 strictly preserve the original HTTP method, like keeping a POST as a POST, while 301/302 have historically been inconsistently reinterpreted by clients as allowing a method change to GET). 308 and 307 were introduced specifically to remove that ambiguity for cases where preserving the method matters.
It's based on how often a status code actually shows up in typical web and API development - codes like 200, 404, and 500 appear constantly in day-to-day work and logs, while codes like 511 or 418 are technically valid and occasionally implemented but rarely encountered outside specific niche situations. This is a practical, not formal, distinction meant to help you gauge whether an unfamiliar code you've encountered is expected or genuinely unusual.
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