The source – youtube.com
Google employee John Mueller during Google SEO Office-Hours answered questions about title length and whether it affects rankings.
The most important things from his answer were:
1. Google doesn't have a specific recommendation for the length of a title.
2. Title tag length is not a ranking factor.
If only a fragment of the title or the content of the title at all is shown in the output, it does not mean that the content of the Title does not affect the ranking.
He expressed bewilderment as to why many services are tied to a certain number of characters in the Title and why it is considered bad if the content is more than 70 characters.