Every platform enforces a hard character limit, but the length that actually performs best is usually shorter than the maximum allowed. Here's both numbers for the platforms that matter most, so you know the ceiling and the sweet spot.
| Platform | Hard limit | Where engagement tends to drop |
|---|---|---|
| X (Twitter) | 280 characters | Under 100 characters performs best; threads bypass the limit entirely |
| Instagram caption | 2,200 characters | First 125 characters show before "more" — that's the effective limit for most viewers |
| LinkedIn post | 3,000 characters | First ~140 characters show before "see more" on feed view |
| Facebook post | 63,206 characters | Posts under 80 characters get noticeably higher engagement on average |
| TikTok caption | 2,200 characters | First 1-2 lines show before "more" on the video view |
| YouTube title | 100 characters | Only about the first 60-70 characters show in search results |
| Pinterest description | 500 characters | First ~50-60 characters show in feed view before truncation |
| Threads post | 500 characters | No separate "see more" truncation — full post typically shows in feed |
Most platforms show a preview of your post in feed view, then require a tap or click to expand the rest ("...more" or "see more"). That preview cutoff — often well under the platform's actual maximum — is the length that determines whether someone reads your full message or scrolls past it. Writing to the hard limit doesn't help if 80% of your audience never taps "more" to see the end of it.
Put your strongest hook, question, or payoff inside that visible preview window. Everything after "more" should be there for the reader who's already engaged — additional context, a call to action, or supporting detail — not the actual point of the post. If the core message only lands after the truncation cutoff, most of your audience will miss it entirely.
Count only the characters up to where your platform's preview typically cuts off (see the table above), and confirm your key point is fully contained in that portion. Everything beyond it should be optional context, not essential meaning.