The length of time you should keep redirect links in place depends on the specific circumstances of the redirect.
If you are redirecting a URL permanently to a new URL, such as when moving a page to a new location or restructuring a site, you should use a 301 redirect and keep the redirect in place indefinitely. This will ensure that users and search engines are always directed to the most up-to-date and relevant content, and that the link equity from the original page is preserved.
If you are using a temporary redirect, such as a 302 redirect, you should only keep the redirect in place for as long as it is necessary. Once the temporary condition that required the redirect is resolved, you should remove the redirect and allow users and search engines to access the original content.
In some cases, you may also need to remove or update redirects if the destination URL changes or if the content on the destination URL is significantly different from the original content. This will ensure that users and search engines are directed to the most relevant and up-to-date content and that link equity is preserved.
Overall, it is important to monitor and maintain redirects regularly to ensure that they are still relevant and useful for users and search engines.