• 200 – OK
• 301 – Moved Permanently
• 302- Temporarily Moved
• 400 – Bad Request
• 401 – Unauthorised
• 403 – Forbidden
• 404 – Not Found

In SEO the header response is very important, and needs to be checked. A great tool to achieve this is the live HTTP headers plugin for firefox.

Once installed you can check the headers of any web page request by clicking on the following logo and ensuring the captcha tick box is checked.

Some of the things to look out for when you are checking the header responses for SEO purposes are:

• Does a link to your site 302 redirect? – a 302 links does not pass any PageRank so will not be as strong
• Do any pages in your site 404? – This means your page no longer exists and should be redirected to pass links juice as well as take your user to the most relevant page
• Does your home page redirect? – If it does you will need to either remove the redirect or change it to a 301
• Does the page redirect more than 5 times? – If it does Google may not be able to follow all the links
• Too many 404 pages or bad request pages may inicate to Google that your site is not trustworthy, which is not a great idea

If the live HTTP headers tool is too technical for you then you might want to use the simpler redirect checker tool located at http://www.internetofficer.com/seo-tool/redirect-check/. This tool is far more simple, simply enter the URL you wish to check and the tool will tell you the type of redirect. The only problem with this tool is you can only look at one redirect at a time so it is more difficult to check multiple redirects.
In the image below I have shown how http://justsearch.co.uk has succesfully been 301 redirect to http://www.justsearching.co.uk to stop canonicalisation issues: