How much content is it safe to change?

[GrouchyKids]

I have read that it is unsafe to change more than 20% of your site’s content in any update.

The rationale is that "Changing too much at once can flag your site within the Google algorithm as having something suspicious going on."

Is this true, has anyone had any direct experiences of this or similar?

[anthonydnelson]

I would have absolutely no concerns over changing your content, as long as you are confident you are changing it for the better.

[GreenStone]

I definitely don't think there's any truth to your site possibly being penalized merely for changing a certain percentage of the site.

However:

• In general, it's always good to change your site in slow increments wherever possible.
• This allows search engine's to slowly adjust to your changes in url structure, content, or site design. Your site wouldn't be "penalized" for it, but considering search engine's have to recrawl your site and adjust to your changes, making sure you don't shock the system by making too many changes is certainly never a bad idea.

[GrouchyKids]

Sorry should have been clearer its when the text changes as part of a redesign.

Still its seems odd to me.

[OlegKorneitchouk]

Haven't heard anything like that before. There are plenty of sites who change more than 20% of a page's content often (news sites, forums, search pages) and aren't penalized.

The only thing you should worry about is if you change more than 20% of the content, Google would recrawl and analyze the text and adjust it's relevance for keyword searches accordingly. So maybe you are getting a lot of traffic from a certain paragraph that you remove when you update the page, your rankings will drop from losing that keyword on the page.