As you can guess, it is with the help of the tag that
og:title you define the title of your content in the snippet. This meta tag performs the same functions as the traditional header tag in your HTML code . It is worth noting that if Facebook and any other social network or instant messenger do not find the og: title tag on your page, they use the usual meta-title, defined through the
<meta property='og:title' content='Your header is here' />
Keep in mind that the text displayed in the snippet will be highlighted in bold , so it is important to make it as attractive and informative to motivate the user to make the transition on the proposed link.
What is the optimal length for an Open Graph header?
The total number of characters is not limited, but it is better to leave the number from 30 to 50 . If your title is longer - it's not scary, the system for creating a snippet will automatically cut off the extra characters, leaving the most necessary.
Use the microdata constructor to evaluate in practice the importance of using the og:title tag when creating an Open Graph microdata.