The ideal length of a tweet is 100 characters
The ideal length of a Facebook post is less than 40 characters
40-character posts received 86 percent higher engagement than others.
It was found significant advantages to ” question posts ” between 100 to 119 characters.
The ideal length of a Google+ headline is less than 60 characters
In the last update, Google changed the layout of posts so that you only see three lines of the original post before you see “Read more” link. In other words, your first sentence has to be a gripping teaser to get people to click “Read More.”
The ideal length of a headline is 6 words. We tend to absorb only the first three words and the last three words of a headline.
The ideal length of a blog post is 7 minutes, 1,600 words
(A photo-heavy post could bring the average down closer to 1,000. Medium’s seven-minute story on ideal post length was filled with images and graphs and contained 980 words.)
What it means is that it’s worth writing however much you really need. Don’t feel constrained by presumed short attention spans. If you put in the effort, so will your audience.
The ideal width of a paragraph is 40-55 characters. ( that’s the length of my previous statement) Content width can give the appearance of simplicity or complexity.
Content width is key to maximizing reader comprehension. The ideal paragraph length, in this sense, would appear simple to the reader and allow for easy reading.
The problem is, to ensure maximum comprehension and the appearance of simplicity, the perfect line length ranges between 40 and 55 characters per line, or in other words, a content column that varies between 250-350 pixels wide (it depends on font size and choice).
Forty and 55 characters per line means about 8 to 11 words.
The ideal length of an email subject line is 28-39 characters. The general rule of thumb in email marketing is to keep your subject line to 50 characters or less. The exception was for highly targeted audiences, where the reader apparently appreciated the additional information in the subject line.
The ideal length of a presentation is 18 minutes. The science behind this 18-minute mark comes from studies of attention spans. Scientists seem to agree on a range of 10 to 18 minutes for how long most people can pay attention before they check out.
It [18 minutes] is the length of a coffee break. So, you watch a great talk, and forward the link to two or three people. It can go viral, very easily. The 18-minute length also works much like the way Twitter forces people to be disciplined in what they write. By forcing speakers who are used to going on for 45 minutes to bring it down to 18 minutes, you get them to really think about what they want to say. … It has a clarifying effect. It brings discipline.
The ideal length of a title tag is 55 characters
Title tags are the bits of text that define your page on a search results page. Brick-and-mortar stores have business names; your web page has a title tag.
Recent changes to the design of Google’s results pages mean that the maximum length for titles is around 60 characters. If your title exceeds 60 characters, it will get truncated with an ellipse. The design change can be seen below where a formerly ideal title has now been truncated.
The ideal length of a domain name is 8 characters.
It is short
It is easy to remember
It is easy to spell
It is descriptive or brandable
It does not contain hyphens and numbers
It has a .com extension
An Alexa report that looked at the domains for the top 250 websites. The results: Over 70 percent of the sites had domain names of 8 characters or less, and the average number of characters per domain was just over 7.
This information by Kevan Lee