301 Permanent Redirect: Explain the Causes and Countermeasures

HTTP status code 301: Causes and solutions for permanent redirection

HTTP status code refers to the status returned by the server to the client during HTTP communication. Numeric code. Among them, status code 301 indicates permanent redirection. When the server performs a permanent location transfer of a resource, it will return a 301 status code to tell the client that it needs to access a new URL when requesting the resource in the future.

So, why is there a need for permanent redirection? There are several main reasons:

1. URL change: If a website changes the URL of a resource, but hopes that users can still access the resource through the old URL, it can use permanent redirection. The purpose of this is to avoid the invalidation of old URLs saved in the user's browser.
2. Domain name change: When a website changes its domain name, but wants users to be redirected to the new domain name when accessing the old domain name, you can use permanent redirection. This maintains continuity of access to the website and avoids the need for users to re-enter new domain names.
3. Website merger: During the process of website merger or reorganization, sometimes the content of multiple original websites needs to be merged into a new website. At this time, in order to allow users to access the content of the new website through the URL of the original website, a permanent redirect can be used.
4. SEO optimization: Search engine optimization (SEO) is a technique that improves the structure and content of a website to improve its ranking in search engines. During the optimization process, sometimes the URLs of some pages need to be adjusted. In this case, permanent redirection can be used to maintain the search engine's indexing effect on the original page and prevent search engines from thinking that the page does not exist or has changed.

Next, let’s take a look at how to properly handle redirects with the 301 status code:

1. Update links: If a URL change occurs, make sure to update all internal links and external links The link is updated with the new URL. When changing URLs, also make sure to update your sitemap and robots.txt files.
2. Set 301 redirect rules: Set 301 redirect rules on the web server to point the old URL to the new URL. This can be achieved by adding redirection rules in the web server's configuration file. For example, in the Apache server, you can use the .htaccess file to set it.
3. Provide friendly prompt information: When the user accesses the old URL, a friendly prompt information should be provided to inform the user that the resource has been permanently transferred to the new URL, and provide a link to the new URL to facilitate the user. Jump.
4. Check whether the redirect is working properly: After redirecting, make sure that the new URL can correctly return the 200 status code and that the page content matches the old URL. At the same time, you should also pay attention to check whether there is an infinite loop redirection or redirection chain problem.

To sum up, the permanent redirection of 301 status code plays a very important role in website operation and maintenance. By correctly handling and using 301 redirects, you can maintain the continuity of website access and improve user experience and search engine friendliness. But at the same time, you also need to pay attention to avoid redirect chains or infinite loops, so as not to affect the normal access to the website.

Reference materials:
https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Status/301
https://zh.wikipedia.org/wiki/ HTTP_301

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