What is a character counter?
A character counter measures the exact length of a piece of text — including spaces and punctuation, not just words — which matters because most social platforms enforce their limits in characters, not words. Writers, social media managers, and anyone posting across multiple platforms use it to confirm a caption or post fits before publishing.
Limits are only half the story
Every platform enforces a hard character limit, but the number that actually determines whether your post performs well is usually much lower than the cap. X truncates nothing until 280, but a caption on Instagram or Facebook that runs past two or three lines gets folded behind "more," and most readers never tap it.
That's why this tool shows every platform's limit side by side instead of just one — a caption you're repurposing across X, Threads, and LinkedIn needs to satisfy the tightest constraint in the group, which is usually X's 280 or TikTok's 150-character caption limit.
If you're writing once and cross-posting, aim for whichever limit is smallest among the platforms you're publishing to, then add platform-specific hashtags or a call-to-action separately where there's room.