How character limits, caption formatting, and bio length actually work across Instagram, TikTok, X, LinkedIn, and Pinterest.
Every social platform enforces text limits differently — some are hard caps that block you from typing further, others quietly fold your text behind a "see more" link once you pass an unwritten threshold. Writing well for social media means knowing which kind of limit you're up against before you start drafting, not after you paste your caption in and watch it get cut off.
This guide covers the practical formatting rules for each major platform and links to the free tool that checks each one.
X and TikTok enforce genuine hard limits — 280 and 150 characters respectively — where the composer simply won't accept more text. Instagram, LinkedIn, and Facebook work differently: their real limits are generous (2,200, 3,000, and over 60,000 characters), but only a fraction of that shows before a "more" link appears. Writing for a hard-limit platform means editing until it fits; writing for a soft-cutoff platform means front-loading the hook into the visible preview window.
Check any draft against seven platforms at once with the Character Counter.
Profile bios are consistently shorter than post limits — Instagram's bio caps at 150 characters versus 2,200 for a caption, and TikTok's bio caps at just 80. A bio is meant to be scanned instantly on a profile page, which is why every platform keeps it tight.
The Bio Character Counter checks a single draft against Instagram, TikTok, X, YouTube, and LinkedIn bio limits simultaneously.
LinkedIn posts fold behind "see more" after roughly 210 characters on mobile — the LinkedIn Post Formatter previews exactly where that happens in your draft. For genuinely long-form ideas meant for X, the Twitter/X Thread Splitter breaks text into numbered, 280-character posts automatically, without ever cutting a post in the middle of a word.
Pinterest pin titles allow 100 characters and descriptions allow 500 — and unlike most social platforms, Pinterest's search leans heavily on the actual text in your description, so using more of that space with relevant keywords tends to help discovery rather than just being extra typing. The Pinterest Pin Description Checker confirms both fields fit before you publish.
Turn keywords into clean, correctly cased hashtags ready to paste.
Check your caption against TikTok's 150-character limit as you type.
Add clean line breaks and a hashtag divider so your caption renders the way you wrote it.
Preview how your line breaks and spacing will actually render in a LinkedIn post.
Split long-form text into numbered, 280-character thread posts automatically.
Check your bio against Instagram, TikTok, X, YouTube, and LinkedIn limits at once.
Check your pin title and description against Pinterest's character limits.
You can, but it's worth checking it against the tightest limit in your posting list first — usually TikTok's 150 characters or X's 280 — since it's easier to expand a short caption for a generous platform than to compress a long one under a tight deadline.