When writing a blog post, the length should be determined by the purpose of the post. If the post is meant to introduce a new subject to readers, then it should be kept short and to the point.
On the other hand, if the post is meant to provide readers with helpful information, then it should be longer. There is no specific length that is perfect for every blog post, but generally speaking, posts that are between 500 and 1,000 words are ideal.