Under construction page bad for SEO?

Question

For our customer we need to develop a brand new website which will replace the current one.

He wants to remove the current 'ugly' site completely and show an underconstruction page untill the new website is ready to launch.

The underconstruction page will contains a little text about the company, contact details, ...

We would redirect all traffic to this page using a 302 redirect. Is this bad for SEO because he already has a lot of traffic and good positions for top keywords? We think this will drop and therefore want to convince the customer to still use his current website untill the release of the new one.

When the new website is launched, all current urls will be redirect with a 301 to the new urls.

Answer 1

Under construction pages are generally no longer used. There is a reason for this. It is an option, however, likely not a good one since you indicated that they have good traffic today. It is far better to retain this traffic flow and not disrupt it.

Most site owners go ahead and develop the new site and leave to the old site until done. From there, when you are deploying the new site, you can use a 301 redirect from valuable links and for high value pages to the replacement pages seamlessly. This retains search value as much as possible without disruption.

Otherwise, while the under construction page exists, even with a 302, you will very likely see a drop in site performance - enough that it may not be easily recovered if at all. Unless the site is totally useless and you simply want to start over and discard old links and search performance, I highly advise not doing what your customer suggested.