Module 2: Captions, limits and hashtagsLesson 4 of 114 min read
Character limits and where your text gets cut
A caption has two limits. The hard one is the number of characters the platform accepts. The soft one comes much earlier: the point where a feed hides the rest behind "more" or cuts a title with an ellipsis. Knowing both, and knowing that not every platform counts the same way, saves you from rewriting a post at the last minute.
The hard limits
YouTube allows 100 characters for a video title and 5,000 for the description. Instagram captions stop at 2,200 characters. TikTok's app accepts captions of up to 4,000 characters, although some scheduling tools still stop at 2,200. Threads allows 500, Bluesky 300, and LinkedIn posts 3,000. On X, free accounts get 280; paid accounts can post longer.
These numbers change. Treat any list, including this one, as a snapshot and check the date it was last reviewed.
Why X counts differently
X doesn't count characters one by one. It gives each one a weight. Most Latin letters, digits and punctuation count as 1. Emoji, and characters such as Chinese, Japanese and Korean, count as 2. Every link counts as 23, however long or short the address is, because X shortens it. Text is normalised first, so an accented letter typed in two parts still counts once.
Most other platforms count characters, where some emoji are built from two or more, and some tools count Threads posts in bytes. Bluesky is the exception that counts what you see: one emoji, even with a skin tone, is 1.
Same text, different counts
"New video 🎬 Full guide: https://example.com/guide" is 23 letters, spaces and punctuation, plus an emoji and a link. X counts it as 23 + 2 + 23 = 48. A plain per-character count gives 49, because the 25-letter link is counted letter by letter and the emoji as 1.
Where feeds cut your text
The soft limits aren't published as fixed numbers because they depend on the screen, the font and the layout. In practice, feeds show one or two lines of a caption before "more", and YouTube cuts long titles after about two lines in most layouts. That's why the first line has to work on its own.
- Put the hook, the keyword or the question in the first line.
- Put links, credits and hashtags at the end, where a cut costs nothing.
- For YouTube titles, front-load the words people search for.
Paste a caption and see how each platform counts it. The example below has an emoji and a link.
Count this captionQuick check
Three questions. Pick an answer to see why.
How many characters does a link use in a post on X?
Show the answer
Answer: 23, whatever its length X shortens links and counts each one as 23.
How does X count most emoji?
Show the answer
Answer: As 2 characters X gives emoji a weight of 2, the same as Chinese, Japanese and Korean characters.
Why put the hook in the first line of a caption?
Show the answer
Answer: Feeds show only a line or two before "more" Everything after that is hidden until someone taps.
Rules change
Platform rules change often. Each guide shows the date it was last checked; when in doubt, the platform's own help page has the final word.
Sources
- X Developer docs – Counting characters
- YouTube Help – Edit video details
- Buffer – Character limits for each social network
- OnlineMarketing.de – TikTok raises the caption limit to 4,000 characters
- Bluesky AT Protocol – post record (300 graphemes)
Last checked October 25, 2026