Instagram character counter
The caption is cut at 125 characters in the feed
The limit is 2,200, but only the first 125 or so show before the more link. Everything that has to be read to make sense of the post belongs before that point, and the rest is for people who already decided to care.
Hashtags count toward the same 2,200
Thirty hashtags at fifteen characters each eat 450 of them. If you write long captions and tag heavily, the ceiling arrives sooner than you expect.
Echoia does the rest: publishing to ten networks, every comment and message in one inbox. Free for three accounts.