HTTP 301
HTTP |
---|
Request methods |
Header fields |
Response status codes |
Security access control methods |
Security vulnerabilities |
The HTTP response status code 301 Moved Permanently is used for permanent URL redirection, meaning current links or records using the URL that the response is received for should be updated. The new URL should be provided in the Location field included with the response. The 301 redirect is considered a best practice for upgrading users from HTTP to HTTPS.[1]
RFC 2616 states that:[2]
- If a client has link-editing capabilities, it should update all references to the Request URL.
- The response is cacheable unless indicated otherwise.
- Unless the request method was HEAD, the entity should contain a small hypertext note with a hyperlink to the new URL(s).
- If the 301 status code is received in response to a request of any type other than GET or HEAD, the client must ask the user before redirecting.
Example
Client request:
GET /index.php HTTP/1.1 Host: www.example.org
Server response:
HTTP/1.1 301 Moved Permanently Location: http://www.example.org/index.asp
Here is an example using a .htaccess file to redirect a non-secure URL to a secure address without the leading "www":
RewriteEngine On RewriteCond %{HTTPS} off RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC] RewriteRule ^(.*)$ http://%1/$1 [R=301,L] RewriteCond %{HTTPS} on RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC] RewriteRule ^(.*)$ https://%1/$1 [R=301,L] RewriteEngine On RewriteCond %{SERVER_PORT} 80 RewriteRule ^(.*)$ https://example.com/$1 [R,L]
Here is an example using a PHP redirect:
<?php
header("Location: https://example.com/newpage.html", true, 301);
exit;
Equivalently simple for an nginx configuration:
location /old/url/ { return 301 /new/url/; }
Here is one way to redirect using Express.js:
app.all("/old/url", (req, res) => { res.redirect(301, "/new/url"); });
Search engines
Both Bing and Google recommend using a 301 redirect to change the URL of a page as it is shown in search engine results.[3][4]
See also
References
- ^ Google. "Secure your site with HTTPS". support.google.com. Google. Retrieved 2016-02-06.
{{cite web}}
:|author=
has generic name (help) - ^ Fielding, et al (1999-06). "10.3.2 301 Moved Permanently". RFC 2616, p 61. IETF, June 1999. Retrieved from https://tools.ietf.org/html/rfc2616#section-10.3.2.
- ^ Site Move Tool - Bing Webmaster Help & How-to - https://www.bing.com/webmaster/help/how-to-use-the-site-move-tool-bb8f5112
- ^ 301 redirects - Google Webmaster Tools Help - https://support.google.com/webmasters/bin/answer.py?hl=en&answer=93633
Bibliography
External links