HTTP Status Codes
Searchable reference of every HTTP status code from 100 to 599 — name, class, and a one-line description.
About the HTTP Status Codes
HTTP Status Codes is a searchable list of the numeric codes a server returns with every response, from 100 Continue up through 511 Network Authentication Required. Each entry shows the number, its official name, and a one-line description of what it means. When you hit a 422 or a 409 in your logs and cannot remember the difference, this page gives you the name and meaning without opening the RFC or guessing from a search engine snippet.
The page loads every code into a single list and filters it as you type. The search box matches against the number, the name, and the description at once, so typing 404, unauthorized, or gateway all narrow the list. Five class buttons (1xx through 5xx) plus an All button restrict the view to one range. Each row is color-coded by class: green for success, amber for client errors, red for server errors, cyan for redirects, gray for informational.
The full status-code reference loads with the page, so it is free, needs no signup, and works offline. The full code list is built into the page, so filtering and searching happen locally with nothing sent to a server. You can keep it open in a tab while debugging an API, glance at it during a code review, or check exactly what your service should return for a given failure. No rate limits, no account, and it works the same whether you are online or offline once loaded.
How to use the HTTP Status Codes
- 1Type a code number, a name, or a keyword into the Search box, for example 404, unauthorized, or gateway.
- 2Read the matching rows: each shows the number in its class color, the official name, and a short description.
- 3Click a class button (1xx, 2xx, 3xx, 4xx, or 5xx) to show only codes in that range.
- 4Combine the two: pick a class button, then type in Search to filter within that range.
- 5Click All to clear the class filter and see every code again.
- 6Clear the Search box to remove the text filter; if nothing matches you will see the No codes match message.
What you can use it for
Decoding an API log
Your client logs a 428 you have never seen. Type 428 and read that the origin requires a conditional request, so you know to add an If-Match header rather than retry blindly or file a bug against the wrong layer.
Picking the right code
You are writing an endpoint that rejects a well-formed but invalid payload. Filter to 4xx and compare 400 Bad Request against 422 Unprocessable Entity to choose the code that describes semantic failure, not malformed syntax.
Redirect debugging
A redirect keeps changing the request method. Click 3xx and scan the list to see that 301 and 302 historically allowed method changes while 307 and 308 require the method to stay the same, which explains the POST that silently became a GET.
Reviewing a teammate's PR
A pull request returns 403 where you expected 401. Search unauthorized and forbidden to confirm 401 means authentication is missing or failed while 403 means the server refuses to authorize an already-identified caller.
Frequently asked questions
Does this send my searches anywhere?
No. The entire code list is embedded in the page and all filtering runs in your browser as you type. Nothing you enter in the Search box is sent to a server or logged. You can confirm this by opening your network tab while you search: no requests fire when you filter the list.
Which codes are included?
Standard registered codes across all five classes, from 100 to 511, including WebDAV codes like 423 Locked and 507 Insufficient Storage, plus 418 I'm a teapot. Vendor-specific codes such as Cloudflare's 520 to 526 or nginx's 444 and 499 are not in the list, so a search for those returns No codes match.
Why does searching 599 return nothing?
The list runs up to 511, the highest standard code, even though the class range nominally extends to 599. Numbers above 511 with no assigned meaning, like 599, are not present. If your search shows No codes match, the code is either non-standard or outside the registered set.
Can I search by meaning instead of number?
Yes. The Search box matches the description text too, so typing rate limit finds 429 Too Many Requests and timeout finds both 408 Request Timeout and 504 Gateway Timeout. Use a keyword when you know the situation but not the number, then read the row to confirm the exact code.
What do the row colors mean?
Each code is tinted by its class: gray for 1xx informational, green for 2xx success, cyan for 3xx redirection, amber for 4xx client errors, and red for 5xx server errors. The class buttons use the same colors, so you can spot at a glance whether a failure is on the client or server side.
Do I need an account or internet connection?
No account and no signup. Because the data ships with the page, once it has loaded the search and class filters keep working without a live connection. There are no usage limits, so you can filter as often as you like while debugging or reviewing code.