HTTP Status Code Checker
Look up any HTTP status code (200, 301, 404, 500…) to see its name, category, plain-English meaning, common causes, and how to fix it — plus a searchable reference of every standard code.
Browse all HTTP status codes
ToolsSoup's HTTP Status Code Checker is a free reference that explains every standard HTTP status code in plain English. Enter a code like 200, 301, 404, or 500 to instantly see its official name, its category (1xx Informational, 2xx Success, 3xx Redirection, 4xx Client Error, or 5xx Server Error), what it means, what commonly causes it, and what to do about it. You can also browse and filter the complete list of status codes from 100 to 511. Everything runs locally in your browser from a built-in reference table — no request is ever sent to the URL or server you are investigating.
What is an HTTP status code?
An HTTP status code is a three-digit number a web server returns with every response to tell the client how the request went. The first digit defines the category: 1xx is informational, 2xx means success, 3xx means a redirect is needed, 4xx means the client made an error (like a bad URL or missing permission), and 5xx means the server failed. Knowing the code turns a vague 'the page is broken' into a precise diagnosis — for example, a 404 means the page was not found, while a 500 means the server itself crashed.
How to look up a status code
Getting an explanation takes seconds:
- Type the status code you saw — for example 404 or 503 — into the input box.
- Click Look up (or press Enter) to see the code's name, category, meaning, common causes, and what to do.
- Or scroll to the browse list and filter by code, name, or category to explore related codes.
The five status code categories
Every status code falls into one of five groups, and the first digit tells you which: 1xx Informational means the request was received and processing continues; 2xx Success means the request was accepted and worked (200 OK is the most common); 3xx Redirection means more action is needed, usually following a new URL (301 and 302 are redirects); 4xx Client Error means something is wrong with the request itself, like 404 Not Found or 403 Forbidden; and 5xx Server Error means the request was valid but the server failed, like 500 Internal Server Error or 503 Service Unavailable.
Why use this HTTP status code checker?
- Covers every standard status code from 100 Continue to 511 Network Authentication Required.
- Explains each code in plain English with its meaning, common causes, and a concrete fix.
- Color-coded by category so you can tell a client error from a server error at a glance.
- Includes a searchable, filterable reference list you can browse by code, name, or category.
- Runs entirely in your browser from a built-in table — it never contacts the URL or server you are checking.
Frequently asked questions
Does this tool check the live status of a URL?
No. It is a reference and explainer, not a live URL checker. Browsers cannot read the status of an arbitrary cross-origin URL because of CORS restrictions, which would require a backend server. Instead, this tool explains any status code you already have — paste the number you saw in your browser's network tab, server logs, or terminal.
What is the difference between 401 and 403?
Both are 4xx client errors about access, but they mean different things. 401 Unauthorized means you are not authenticated — your credentials are missing, expired, or invalid, so the server does not know who you are. 403 Forbidden means you are authenticated but not allowed — the server knows who you are and is refusing the action. In short, 401 is about identity and 403 is about permission.
What is the difference between 301 and 302?
A 301 Moved Permanently means the resource has a new permanent home, so browsers and search engines update and cache the new URL. A 302 Found is a temporary redirect, so clients keep using the original URL for future requests. Use 301 when you have moved a page for good, and 302 (or 307) when the move is only temporary.
What does a 500 error mean and how do I fix it?
A 500 Internal Server Error means the server hit an unexpected problem and could not complete the request — usually an unhandled exception, a bug, or a misconfiguration in the application code. Because the failure is on the server side, the fix is to check the server logs to find the underlying error, correct the bug or configuration, and redeploy.
Is my data sent anywhere when I look up a code?
No. The entire reference table is built into the page and all lookups happen locally in your browser with JavaScript. Nothing you enter is sent to any server, and no request is made to the URL you are investigating.