A character limit is the maximum number of characters — letters, numbers, symbols, spaces, and emoji — allowed in a single post, bio, caption, or other text field on a social media platform. Understanding these limits is essential for brands that publish across multiple channels, because each platform enforces different caps that directly affect how your message appears to audiences.

What is a character limit?

Every social media platform sets a hard cap on how long certain text elements can be. When you hit the character limit, the platform either stops accepting input or truncates your content behind a “see more” prompt. The term covers all types of characters: standard letters and numbers, punctuation, spaces between words, and even emoji (which can count as two or more characters depending on the platform’s encoding).

Character limits exist to keep feeds scannable. They evolved from technical constraints — Twitter’s original 140-character cap mirrored SMS message lengths — but they’ve become a fundamental part of how each platform shapes user behavior and content style.

Current character limits by platform (2026)

Limits change frequently as platforms update their features and subscription tiers. Here are the current limits as of February 2026:

X (formerly Twitter)

  • Free users: 280 characters per post
  • Premium subscribers: up to 25,000 characters per post
  • Bio: 160 characters
  • Display name: 50 characters

Instagram

  • Captions: 2,200 characters (only the first ~125 display before “more”)
  • Bio: 150 characters
  • Comments: 2,200 characters
  • Hashtags: up to 30 per post

TikTok

  • Captions: 4,000 characters
  • Bio: 80 characters
  • Comments: 150 characters

Facebook

  • Posts: 63,206 characters (but optimal engagement is under 80 characters)
  • Comments: 8,000 characters
  • Ad primary text: 125 characters before truncation

LinkedIn

  • Posts: 3,000 characters (first ~210 shown before “see more”)
  • Articles: 125,000 characters
  • Headline: 220 characters

Threads (Meta)

  • Posts: 500 characters

Bluesky

  • Posts: 300 characters

For a deeper look at platform-specific best practices, see our guides on Instagram best practices and TikTok tips.

Why character limits matter for brands

For social media teams managing multiple platforms, character limits aren’t just a technical detail — they shape content strategy. A post crafted for LinkedIn’s 3,000-character allowance won’t work as a 280-character X update. Brands that ignore these differences end up with truncated messages, awkward cuts, or posts that lose their call to action behind a “see more” fold.

Character limits also affect visibility. On most platforms, the text visible before truncation determines whether someone stops scrolling. On Instagram, that’s roughly 125 characters. On LinkedIn, about 210. If your hook doesn’t land in that window, the rest of your post may never be seen. This is why social media managers front-load key messages — the limit isn’t just about length, it’s about attention.

Brands using a social media management platform can adapt content per channel while maintaining a consistent message. That means knowing each platform’s constraints before scheduling a single post.

How to work within character limits

Rather than seeing limits as obstacles, treat them as editing constraints that sharpen your message:

  • Front-load the hook. Put the most important idea in the first line. On every platform, the opening text determines whether someone reads further or keeps scrolling.
  • Tailor per platform. A strong Instagram caption won’t work as an X post. Adapt the format and length, not just copy-paste and trim.
  • Account for hidden characters. Hashtags, @mentions, and URLs all count toward the limit. On X, every link uses 23 characters regardless of actual URL length.
  • Use line breaks strategically. On LinkedIn and Instagram, white space makes longer posts more scannable — but those line breaks count as characters too.
  • Write your social media bios separately. Bio character limits (80-160 characters depending on platform) demand distilled messaging that differs from post copy. Don’t try to repurpose one for the other.
  • Test and measure. Track which post lengths drive the most engagement on each platform. The optimal length is often well below the maximum — on X, posts between 70-100 characters tend to see higher engagement rates than those using the full 280.

For teams working across multiple channels, consistency comes from understanding the constraints of each. Explore the full social media glossary for more terms that shape how brands communicate online.