LinkedIn Caption Optimizer

What LinkedIn's feed rewards

Dwell time is the signal that separates a post that reaches 400 people from one that reaches 40,000. LinkedIn measures how long someone stays on your post, and the "see more" expansion is the clearest expression of that. A hook that earns the expansion, followed by a post worth the seconds, is the entire game.

Comments in the first hour matter disproportionately, and comments with substance count more than "Great post!". Ending with a question aimed at a specific group — "agency owners: how do you price this?" — reliably outperforms a general prompt.

The feed is professional but not formal. The posts that work read like a smart person talking, not a press release. Corporate register is the most common reason a well-structured LinkedIn post gets no traction.

Length, formatting, and links

The cap is 3,000 characters. The useful range is 800 to 1,500 for a substantive post, or under 300 for a sharp observation. Somewhere in the middle — long enough to require expansion, short enough to disappoint after it — is the worst place to land.

Format for a phone. Single-sentence paragraphs, a blank line between them, no more than about three lines in a row. LinkedIn strips most rich formatting, so structure comes from line breaks and nothing else. Unicode bold characters are accessibility-hostile and screen readers mangle them — avoid them.

External links in the post body have historically suppressed reach. Putting the link in the first comment and referencing it in the post is still the safer pattern, and it costs you almost nothing.

Three hashtags is the working number. They function as topic labels rather than discovery channels, so pick broad, real ones and stop.

Common LinkedIn caption mistakes

The manufactured vulnerability opener. "I got rejected 47 times and here's what it taught me" is now so pattern-matched that it reads as a template regardless of whether it is true.

Burying the point behind three lines of setup. If the first 140 characters are scene-setting, nobody expands.

Broadcasting a link with no post. "Check out our new blog post 👇" is the lowest-performing format on the platform.

Tagging people who have nothing to do with the post. It notifies them, annoys them, and LinkedIn discounts engagement it thinks was solicited.