Optimal post length guide
Quick reference for optimal content length on every platform — character counts, ideal word counts.
Optimal: 71–100 chars
Optimal: 1,300 chars. 'See more' at ~210
Optimal: 138–150. Shows ~125 before 'more'
Optimal: under 80 chars for max reach
Optimal: 100–150 chars
Optimal: 60 chars (avoids truncation)
Only 50 chars show in grid
Similar to Twitter — short wins
Short, punchy — Twitter replacement vibes
Instance-configurable
Long-form works well in channels
about the optimal post length guide
Every platform has two numbers that matter: the hard limit (what you're allowed to post) and the optimal length (what actually performs). They're rarely the same. Facebook allows over 60,000 characters, but its best-performing posts are often under 80. Writing to the limit instead of the sweet spot is one of the most common reasons decent content underperforms.
The hard limits: X allows 280 characters (25,000 for Premium), LinkedIn 3,000, Instagram captions 2,200, and TikTok captions 4,000. The sweet spots are smaller: tweets under about 100 characters tend to earn more engagement, LinkedIn posts do best around 150-250 words (with the crucial hook in the first ~200 characters before the "see more" fold), and Instagram captions front-load their message because only the first couple of lines show before "more."
Use this guide as a pre-publish checklist: draft your post, check it against the platform's optimal range, and trim or expand accordingly. Then queue everything in PostAI — writing each platform's version once and scheduling them together beats reformatting the same post five times on posting day.
frequently asked questions
What are the character limits for each social media platform?
X: 280 characters (25,000 for Premium subscribers). LinkedIn posts: 3,000. Instagram captions: 2,200. TikTok captions: 4,000. Facebook: 63,206. Mastodon defaults to 500. Bios are far shorter — 160 on X, 150 on Instagram, 80 on TikTok.
What is the ideal length for a LinkedIn post?
150-250 words for most content. LinkedIn truncates posts at roughly 200 characters with a "see more" link, so the opening lines must work as a standalone hook. Long-form (1,000+ words) can work for deep expertise content, but concise posts with a strong hook win more consistently.
Do shorter posts get more engagement?
Usually, but it's really about density, not brevity — every line must earn its place. Short posts win on X and Facebook because feeds move fast; on LinkedIn and Instagram, medium-length posts that tell a complete story outperform one-liners. Match length to the platform's reading behavior.
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