Google rewrites meta descriptions for pages over 70% of the time, according to a recent study examining search results for 30,000 keywords.
Portent analyzed mobile and desktop search results to find Google rewrites meta descriptions at a rate of 71% on mobile, and 68% on desktop.
Based on the data, it’s reasonable to deduct that Google will use a page’s own meta description around 30% of the time.
Meta Description Rewrite Rate by Search Position
Data from the study focuses primarily on the first page of organic search results, excluding featured snippets.
Portent notes there’s a bump in the rate of meta descriptions rewrites from positions 4 to 6, which may be due to Google trying to boost relevance of those results.
“I speculate that since positions 1-3 get the most click-through rate, Google might be trying to boost the relevance for 4-6 to get more clicks before users leave the page or search for something else.”
So meta descriptions are likely to be rewritten more frequently depending on where the pages rank.
Meta Description Rewrite Rate by Search Volume
Trends were observed when examining the relationship between rewrite rate and search volume.
Notably, the higher the search volume, the less likely Google is to rewrite the meta description.
Portent speculates this is because SEOs prioritize writing meta descriptions for keywords with the most searches per month.
“So why do we see this relationship? I think it’s because SEOs tend to focus on writing meta descriptions for head terms more than the long-tail…
You’re probably not hyper-focusing on the 10 searches per month terms, and they probably vary too much to even target with any one description.”
Meta Description Display Length
Another factor that can vary when it comes to meta descriptions is how many characters Google chooses to display.
On desktop, it was found that displayed characters peak at 156 and drop off sharply after 165.
That number could drop to around 142 characters if a date is displayed in the snippet.
When Google rewrites the meta description it’s likely to display between 160 to 167 characters. With dates, the range is between 147 to 149 characters.
Clearly, Google is giving itself more room to work with when writing meta descriptions than it gives to site owners.
On mobile, displayable characters for snippets without a publication date peak at 118 and drop off after 121.
Meta description length on mobile for snippets with a publication date fall somewhere between 95 to 105 characters.
When Google rewrites the meta description on mobile it will display around 114 to 121 characters. With dates, the range is between 99 to 105 characters.
What can SEOs do with all this new data about meta descriptions?
Here’s what Portent recommends:
- Keep meta descriptions between 150 and 160 characters for regular pages.
- Keep meta descriptions for blog posts between 138 to 148 characters (and other pages with publication dates).
- Put the most important information within the first 100 characters.
Regardless of Google using site owners’ meta descriptions only 30% of the time, it’s important not to give up on writing them.
For more data and insights, see the full study here.
Learn more about why Google rewrites meta descriptions in this explainer from Search Engine Journal’s Roger Montti.
Learn what site owners can do to avoid meta description rewrites in an article I wrote earlier this year.