HTTP Status Codes Reference
Search every HTTP status code, see what it means, and copy it with a click.
Type a code, a partial code like 40, or any word from a name or description. Everything runs in your browser.
69 of 69 codes. Click a row to copy it.
How to look up an HTTP status code
Search a code
Type a code like 404, a partial code like 40, or a word like timeout to filter the list instantly.
Filter by class
Narrow the list to 1xx, 2xx, 3xx, 4xx, or 5xx responses with one click on the class buttons.
Copy the code
Click any row to copy the code, or the code with its name, straight to your clipboard.
Why use this tool
Every standard code
Covers the registered HTTP status codes from 100 Continue to 511 Network Authentication Required, each with a plain-English one-line description.
Instant search
Matches partial codes like 40 as well as names and descriptions, so you can find a code without knowing its exact number.
Non-standard codes labelled
Widely seen unofficial codes, including 444, 499, and the 520 to 524 gateway range, are included with a clear label showing where they come from.
Copy in your format
Click any row to copy either the bare code or the code with its name, and copy the whole filtered list in one action.
Runs entirely in your browser
The whole reference lives on the page. Nothing is looked up remotely and nothing you type is sent anywhere.
About this tool
Every developer ends up searching what 502 means, or the difference between 401 and 403, more times than they would like. This reference puts the full set of HTTP status codes on one page: every registered code from 100 to 511, grouped into its five classes, each with its official name and a one-line plain-English description. Type into the search box and the list filters as you go, matching partial codes like 40, names like Forbidden, or words from the descriptions like cache or timeout.
The list also includes the unofficial codes you actually meet in the wild. Server codes 444 and 499 and the 520 to 524 gateway range appear with a clear label showing which software they come from, so you can tell a registered code from a vendor convention at a glance. Filter buttons narrow the view to a single class, and a toggle hides the descriptions when you just want a compact list of codes and names.
Every row copies with a click, either the bare number or the code and name together, depending on the copy format you pick. The full filtered list can be copied in one action too, ready to paste into documentation, tests, or an error-handling switch. If you are debugging requests more broadly, the MIME type lookup and the common port numbers reference cover two other lookups that tend to come up alongside status codes.
Frequently asked questions
- What do the status code classes mean?
- The first digit groups codes by meaning: 1xx is informational, 2xx means success, 3xx is a redirect, 4xx is a client-side error such as a bad request or missing page, and 5xx is a server-side error.
- What is the difference between 401 and 403?
- 401 Unauthorized means the request lacks valid credentials, so authenticating may fix it. 403 Forbidden means the server knows who you are and still refuses, so logging in again will not help.
- Are codes like 444, 499, and 520 real HTTP status codes?
- They are not in the official registry. 444 and 499 are conventions used by a popular web server, and 520 to 524 are used by a large CDN. They are included here with labels because they show up constantly in real logs.
- What is the difference between 301 and 308?
- Both are permanent redirects, but 308 requires the client to repeat the request with the same method and body, while clients following a 301 often change a POST into a GET.
- Is anything I type sent to a server?
- No. The entire reference is built into the page and searching happens in your browser; nothing is uploaded or logged.
- Can I copy several codes at once?
- Yes. The button at the bottom copies every code currently matching your search and class filter, one per line, in the copy format you selected.
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