HTTP Status Codes
Numeric codes returned by a web server indicating the status of a request.
HTTP status codes are three-digit codes returned by a web server in response to a browser or crawler request. They indicate whether the request was successful, if a redirect is needed, or if an error occurred.
Important categories
2xx (Success): 200 OK is the standard success response. 3xx (Redirect): 301 (permanent) and 302 (temporary) redirect visitors and bots. 4xx (Client error): 404 (not found) and 410 (gone). 5xx (Server error): 500 and 503 indicate server problems.
SEO impact
Wrong status codes can seriously harm your SEO — bibliotheekterm. A page returning 200 but showing an error message (soft 404) wastes crawl budget. Too many 5xx errors can reduce your crawl rate. Correct redirects (301) pass link value.
Complete reference table
| Code | Name | Meaning | SEO impact |
|---|---|---|---|
| 200 | OK | The request was successfully processed. The server returns the requested content. | Positive: the page is accessible and indexable. |
| 301 | Moved Permanently | The page has permanently moved to a new URL. | Passes link value (PageRank — bibliotheekterm) to the new URL. Use for permanent moves. |
| 302 | Found (Temporary Redirect) | The page is temporarily available at a different URL. | Does not pass link value. Google may treat long-standing 302s as 301s over time. |
| 304 | Not Modified | The page has not changed since the last request. Browser may use cache. | No direct SEO impact. Reduces server load and crawl time. |
| 307 | Temporary Redirect | Temporary redirect that preserves the HTTP method (POST stays POST). | Similar to 302 but technically stricter. Rarely used for SEO. |
| 308 | Permanent Redirect | Permanent redirect that preserves the HTTP method. | Similar to 301 but preserves the HTTP method. Suitable for APIs. |
| 400 | Bad Request | The request is invalid or cannot be processed. | Page won't be indexed. Verify legitimate URLs don't return 400. |
| 401 | Unauthorized | Authentication is required to view the page. | Page won't be indexed. Use for content behind login. |
| 403 | Forbidden | The server refuses the request, even after authentication. | Page won't be indexed. Verify public pages don't return 403. |
| 404 | Not Found | The page doesn't exist or wasn't found. | Google removes the page from the index — bibliotheekterm after repeated 404s. Occasional 404s are normal. |
| 410 | Gone | The page has been permanently removed and won't return. | Google removes the page from the index faster than with a 404. Use for deliberately deleted content. |
| 429 | Too Many Requests | The client has sent too many requests (rate limiting). | Crawlers slow down on 429 responses. Ensure Googlebot isn't blocked by rate limiting. |
| 500 | Internal Server Error | An unexpected error occurred on the server. | Repeated 500 errors can lead to deindexing. Google reduces crawl rate. |
| 502 | Bad Gateway | The server received an invalid response from an upstream server. | Temporary 502s are normal during deployments. Repeated 502s are a serious problem. |
| 503 | Service Unavailable | The server is temporarily unavailable (maintenance, overload). | Google retries later. Use 503 + Retry-After header for planned maintenance. |
Decision tree: which redirect to use?
- Is the move permanent? (old URL won't come back)
- Yes → Use 301 Moved Permanently. This passes link value and tells search engines to index the new URL.
- Is the move temporary? (e.g., A/B test, maintenance, seasonal page)
- Yes → Use 302 Found. The original URL retains its place in the index.
- Is it an API endpoint where the HTTP method must be preserved?
- Permanent → 308 Permanent Redirect
- Temporary → 307 Temporary Redirect
- Is the page permanently removed without a replacement?
- Yes → Use 410 Gone (faster deindexing than 404).
- Is the page not found but might return later?
- Yes → Use 404 Not Found.
Frequently asked questions
Is a 302 redirect bad for SEO?
Not necessarily, but a 302 officially doesn't pass link value. In practice, Google often treats long-standing 302s as 301s. But if you know the move is permanent, always use a 301 to avoid ambiguity.
How many 404 pages are acceptable?
Occasional 404s are normal and don't damage your SEO. Google distinguishes between "real" 404s (pages that never existed) and pages that recently existed. Ensure important pages with incoming links are always redirected via a 301.
What is a soft 404?
A soft 404 is a page that returns a 200 status code but is actually an error page (e.g., showing "Page not found" text). Google detects soft 404s and wastes crawl budget on them. Ensure error pages return an actual 404 status code.
How do I find status code errors on my site?
Use Google Search Console (Coverage report), Screaming Frog (crawl your own site), or Chrome DevTools (Network tab). Search Console specifically reports server errors (5xx) and not-found pages (404) that Google encounters.
Are status codes relevant for AI bots?
Yes. AI bots like GPTBot and ClaudeBot respond to status codes just like search engines. A 403 or 429 blocks the bot, a 301 is followed, and a 503 leads to a later retry. Make sure your rate limiting doesn't unintentionally block AI bots.
