Not long after Google increased the length of the ‘search snippets’ displayed in the search results, they now revert to the shorter search snippets. Around December 2017, Google increased the length of the search snippets to around 320 characters. The move was unannounced, but was visible for most search queries. Webmasters around the world hurried to update the Meta Description tag on their pages to reflect the new change, some to the degree of updating hundreds of pages on their websites.
Google is often testing features, and it seems that they decided to revert the search snippets to around 160 characters – literally cutting the snippets in half.
Google officials confirmed this change, stating the snippets are now shorter, though slightly longer then before the change from six months ago. There is no fixed length for snippets, and web developers should not have changed the meta description tags. These things change by device and by search query, and it might change again in the future.