HTTP Status Code Reference
Look up any HTTP response status code by number or keyword and get a short explanation of what it means, the situations that usually cause it, and what to check next. The list covers the standard codes from RFC 9110 and related specifications, plus the ones you are likely to meet from proxies and CDNs, and filters as you type.
Look Up an HTTP Status Code
Status codes
How to Use the HTTP Status Codes
- Type a code (such as 404) or a word (such as redirect, auth or timeout).
- Optionally limit the list to one class, for example 5xx server errors.
- Read the meaning, typical causes and what to check for each matching code.
About This Tool
Web developers debugging APIs and websites, SEO specialists auditing redirects and errors, and support staff explaining an error page to a customer.
Input: Code or keyword · Output: Matching status codes.
Features and Limitations
Features
- More than 60 status codes with original plain-English explanations.
- Typical causes and next steps for each code, not just the official name.
- Instant filtering by number, name or keyword, with the number of matches announced.
- Marks codes that matter for SEO, such as 301, 302, 404, 410 and 503.
Limitations
- Servers sometimes use codes loosely (for example 200 for error pages, or 500 for everything), so the real cause can differ from the typical one.
- Vendor-specific codes beyond the most common CDN and server ones (such as Cloudflare's 52x range) are not all included.
- Results are computed in your browser; nothing you enter is sent to a server.
Example
Searching “redirect” lists 300, 301, 302, 303, 304, 307 and 308 and explains that 301 and 308 are permanent while 302 and 307 are temporary.
Frequently Asked Questions
What is the difference between 301 and 308?
Both are permanent redirects. With 301, browsers may change a POST request into a GET when following it; 308 requires the method and body to stay the same.
Should a missing page return 404 or 410?
404 says the page is not found; 410 says it is gone on purpose and will not return. Search engines treat both as removal, 410 sometimes slightly faster.
What is a soft 404?
A page that says “not found” but returns 200 OK. Search engines may index it as an empty page, so return a real 404 or 410 status for missing content.
When should a site return 503?
During planned maintenance or overload. Add a Retry-After header so crawlers and clients know when to come back.
Related Tools
More like this: all URL & HTTP tools, all Developer & Web tools or the TinySandy home page.