HTTP Status Code Reference

How HTTP Status Code Reference works, step by step

1

Type a status code number or a keyword into the search box.

2 Download it

Read the code's official name, category and plain-English meaning.

HTTP Status Code Reference — Every Code Explained

Every response an HTTP server sends starts with a three-digit status code, and every one of those codes is officially defined by web standards (RFC 9110 and related specs) with a specific real meaning — 200 means success, 404 means the resource wasn't found, 500 means the server itself failed. This reference lists every standard code across all five categories (1xx informational, 2xx success, 3xx redirection, 4xx client error, 5xx server error), with its official name, a plain-English explanation, and the most common real-world situations that actually trigger it.

Search by typing a number (like 403) or a keyword (like "not found" or "rate limit") to jump straight to the code you're debugging, instead of scrolling a long static list. Each entry also notes what a developer, and separately what an end user, should typically do when they hit that specific code.

Key features

How to use it

1. Type a status code number or a keyword into the search box.
2. Read the code's official name, category and plain-English meaning.
3. Check the common real-world causes listed for that code.
4. Use the suggested next step if you're debugging it yourself.

Worked example

Example

Search "429" -> Too Many Requests: the client has sent too many requests in a given time window (rate limiting); common causes include an API being called too frequently or a bot-protection trigger; the fix is usually to slow down requests or respect a Retry-After header.

Who uses this tool

Tips for the best results

• 4xx codes mean the client's request was the problem (bad URL, missing auth, malformed data); 5xx codes mean the server itself failed to fulfill a request that was otherwise fine — that distinction is the fastest way to know where to start debugging.
• A 200 status doesn't guarantee the response body was actually what you expected — some broken APIs return 200 with an error message inside the body, which is against best practice but does happen.
• 3xx redirects have important sub-differences (301 permanent vs 302/307 temporary) that matter a lot for SEO and caching, not just for whether the browser follows them.

Common mistakes to avoid

• Assuming every error is a "500" or server problem — a very large share of real-world errors are actually 4xx client-side issues like a wrong URL, missing header, or expired auth token.
• Confusing 401 (Unauthorized — you're not authenticated at all) with 403 (Forbidden — you are authenticated but not allowed to access this specific resource).
• Ignoring a 429's Retry-After header and hammering the same endpoint again immediately, which usually extends the rate-limit penalty.

Frequently asked questions