The ideal length for picture captions is up to 125 characters.
As for hashtags? While the platform allows 30 hashtags per post, 11 seems to be the magic number to optimise engagement.
![hashtags on instgram](https://s3.amazonaws.com/cooalaLIVE/hotstuff/79029_TEASER_5_medium.jpg)
[SumAll](http://blog.sumall.com/) and [Buffer](https://buffer.com/) analyzed the top 50 YouTube videos and found that the average length was [2 minutes and 54](http://www.socialmediatoday.com/marketing/carianneking/2015-07-07/what-ideal-length-everything-online-infographic) seconds.
But [Wistia](https://wistia.com/blog/optimal-video-length) reported that engagement is steady up to **2 minutes**.
For a video of 4-5 minutes, fewer than 60% of your viewers will still be with you at the end âcontrasting strongly with 75% for a 1-2 minute video.
And donât over-tag! [Google](https://support.google.com/youtube/answer/6390658) will ignore all video hashtags when it has more than 15!
*Graphic Sources: Source1: Photo byÂ NeONBRANDÂ onÂ Unsplash // Source2: [Buffer Social](https://blog.bufferapp.com/a-scientific-guide-to-hashtags-which-ones-work-when-and-how-many) // Source3: [Socialbakes]() retrieved from [Track Maven](https://d25qe19fo1nsn4.cloudfront.net/wp-content/uploads/2015/07/YouTube-Video-Views.png) //