301 Redirects
A 301 redirect is a permanent redirect. It is used when a requested resource has been moved permanently to a new URL and any future references to this resource should use one of the returned URLs. This type of redirect takes place on both a browser and server level. It’s the most commonly used and powerful redirect. It passes on all the SEO authority of the existing URL. And search engines recognize and index this kind of redirect, making it the best choice for SEO.
In almost all cases, this is the type of redirect you’ll want to use.
302 Redirect
A 302 redirect is a temporary redirect. It should only be used when you have the intention of moving back to the old URL at some point. If, for example, you’re redesigning your site, but want to direct users to a different domain while you finish. Or if you want to A/B test two different versions of a page, before committing to a new version.
302 redirects aren’t used very often. If you’re considering using a 302 redirect, consider carefully whether you might be better off using a 301 redirect.
404 Redirects
A 404 error implies that the requested URL may be available again in the future, but not necessarily with the same content.
Meta Refresh
Have you ever landed on a page and been greeted with a message that says, “The original URL has moved, you’re now being redirected. Click here if you’re not redirected in 5 seconds”? Then you’ve experienced a meta refresh.
A meta refresh is a redirect that functions by telling the browser to go to the new page, without updating the server. When setting up a meta refresh, you can clarify the amount of time it should take for the redirect to the new page to occur. Sometimes search engines interpret a meta refresh in the same way as a 301 redirect, especially if the time allotted is zero or one second. But it’s not entirely consistent how search engines read a meta refresh, and they create a worse user experience by making the visitor wait to get to the page they’re seeking.
In instances where you’re considering a meta refresh, you’re likely to be better off with a 301 redirect.