HTTP Status Codes Explained: What 200, 301, 404, and 500 Actually Mean

What a Status Code Actually Is

Every time a browser requests a page, image, or file from a server, the server responds with a three-digit status code before it sends anything else. Visitors never see this number directly, browsers just render the page or show an error, but it's the mechanism behind nearly every "page not found" or "something went wrong" message, and search engines read it directly to decide how to treat a page.

The Five Ranges, at a Glance

Status codes are grouped into five ranges by their first digit:

• 1xx: Informational. Rare in normal browsing; the request is still being processed.
• 2xx: Success. The request worked as expected.
• 3xx: Redirection. The requested content is somewhere else now.
• 4xx: Client error. Something about the request itself was wrong, most often a page that doesn't exist.
• 5xx: Server error. The request was fine, but the server failed to handle it.

200 OK: The Good Outcome

200 is the code behind almost every successful page load. It simply means the server found what was requested and sent it back successfully. It's invisible in normal browsing precisely because it's the expected outcome.

3xx: Redirects

A 3xx code tells the browser the content has moved somewhere else. The two you'll encounter constantly are 301 (permanent) and 302 (temporary), and the difference between them matters more than it might seem, particularly for SEO. See our full guide to 301 vs. 302 redirects for when to use each.

404: Not Found

404 means the server has no content at the requested address. It's the most familiar error code by far, usually caused by a deleted page, a mistyped URL, or a link pointing somewhere that no longer exists. A 404 isn't necessarily a sign anything is broken; it's the correct, honest response when something genuinely isn't there.

500: Internal Server Error

500 means the server itself failed while trying to handle an otherwise-valid request, commonly from a plugin conflict, a coding error in custom code, a database connection failure, or the server running out of memory. Unlike a 404, a 500 error usually does mean something needs fixing on the site's end, and is worth investigating rather than ignoring.

Other Codes Worth Knowing

A few others come up often enough to recognize:

• 401 Unauthorized: the request needs valid login credentials that weren't provided.
• 403 Forbidden: the server understood the request but is refusing to fulfill it, often a permissions issue or a security rule blocking access.
• 429 Too Many Requests: the client has sent too many requests too quickly, a rate-limiting response often seen when a security tool is blocking automated traffic. See our guide to common website attacks for the kind of automated traffic this is usually blocking.

Why Status Codes Matter for SEO

Search engines crawl a site using these codes to decide what to do with each page: index a 200, follow and re-credit a 301, keep the original URL for a 302, and eventually drop a page from the index after repeated 404s. A page that's actually working fine but accidentally returns the wrong code, for example a 200 on an error page, can confuse this process and hurt visibility in ways that have nothing to do with the page's actual content.

How to Check What Your Site Is Returning

Browser developer tools show the exact status code for every request a page makes, under the Network tab. For a quicker check on any public URL, a free online HTTPHyperText Transfer Protocol — the rules browsers and servers use to request and send web pages. header checker shows the code without needing developer tools at all, useful for confirming a redirectA server instruction that automatically sends a browser from one URL to another. is set up correctly or spotting a page that's quietly returning a 404 or 500 when it shouldn't be.