I got a bunch of domains of the form mywebsite.com, mywebsite.biz, mywebsite.org. As of now, 1 of them is javascript redirect, and the other 5 are parked.
Will javascript redirecting all of them to my main website (otherurl.com), help or hurt my SEO?
Will javascript redirecting all of them to my main website (otherurl.com), help or hurt my SEO?
Client-side javascript redirects and the similar meta-refreshes are strongly associated with deceptive practices by Google. There are still some narrow circumstances where Google are ok with you using them but they strongly recommend that you use server-side "HTTP response status code 301 Moved Permanently" redirects instead. There is much debate amongst SEO industry experts about the exact impact of them but they are generally considered high-risk for low if any reward.
If your non-main domains have no content yet then they are irrelevant as regards SEO as they have no content to crawl and index. Google only cares about good quality content, nothing else.
If you simply want to have multiple domains all pointing to the same content then the 301 redirect discussed below is the Google-approved way to do that.
Assuming you want a permanent redirect as opposed to a temporary one...
The only kind of redirect that will not harm your SEO is a "HTTP response status code 301 Moved Permanently".
"HTTP response status code 301" is a HTTP server response code and can only be sent from a server. There are multiple ways of doing this (including server-side javascript).
"HTTP response status code 301" cannot be achieved by running javascript in the HTTP client (aka the web browser)
website under construction, thank you for using registrar page?
– Mikhail
May 29 '15 at 2:07
There are two options.
If you want to continue using Javascript redirects, then between <head> and </head> in your HTML code with javascript redirect code, add:
<link rel="canonical" href="resultingurl">
<meta name="robots" content="noindex">
but replace "resultingurl" with the full URL to the URL javascript redirects the page to.
At least this way, you're pointing out to google that the first page is the duplicate of the new page and you prefer the new page to be indexed. Also, you're specifically telling all search engines not to index the first page. Therefore, no chance of duplication issues.
But if you want to create a better user experience, implement HTTP redirects so that users don't need javascript to view your site. The only advantage to javascript is if you had a wonderful introduction screen you want people to see before visiting the main site.
You can easily use PHP to do this by creating index.php with the following contents:
<?php
$newurl="http://example.com";
header("HTTP/1.1 301 Moved Permanently",true);
header("Location: ".$newurl,true);
?>
Save the file in document root to make the main domain redirect to the new one.
Replace example.com in the code with the new url the first url is supposed to redirect to.
Whatever you do, just make sure the duplicate pages (copies of the same pages with an HTTP 200 status code) are no-indexed.
The SEO aspect of this question really comes down to how strong the alternate domains are and their history.
If they're just alternates of the original domain and never held any content themselves (as is often the case) then you're really just covering yourself from domain squatting & leakage. There won't be any value to the alternates so there's no real value to flow through to your primary.
