On Twitter, Google’s Danny Sullivan said that the snippets on Google’s result pages are no shorter on average than in recent weeks. Tests show that the average snippet length is about 160 characters for desktop search results and about 130 characters for mobile search results.
Our search snippets are now shorter on average than in recent weeks, though slightly longer than before a change we made last December. There is no fixed length for snippets. Length varies based on what our systems deem to be most useful.— Danny Sullivan (@dannysullivan) 14. Mai 2018
Danny Sullivan also said that the length of snippets is dynamic and that there is no maximum length:
The length of snippets is dynamic. We're not stating a maximum length because of this.— Danny Sullivan (@dannysullivan) 14. Mai 2018
What should you do now?
If your meta descriptions are longer than 160 characters, chances are that Google’s won’t show the full description on the search result pages. A good description can increase the number of clicks that a web page gets on Google’s results page.
Google only uses the meta description if it is relevant to the search query. If the meta description is not relevant, Google will create a snippet that is based on the content of the web page. If you want to be listed with good descriptions on Google’s result pages, you should create relevant web pages with relevant content and relevant descriptions. The web page optimization tools in SEOprofiler help you to improve your pages: