Character Limits for Social Media and SEO, at a Glance

X (Twitter) posts: 280 characters, counted by Unicode code point, so most emoji and accented letters count as one character each. Go over and the post simply can't be submitted.

SMS: 160 characters per message segment using standard GSM encoding. Text past 160 characters and it splits into multiple linked segments of 153 characters each, rather than failing outright — which is why very long texts can cost more to send or arrive out of order on older carriers.

Instagram captions: a hard cap of 2,200 characters, though only the first ~125 characters show before 'more' truncates the rest in the feed — the practical limit for a caption people actually read is far lower than the platform's technical maximum.

SEO meta title: no hard character cap, but Google typically renders around 50–60 characters (roughly 580 pixels) before truncating with an ellipsis in search results.

SEO meta description: similarly no hard cap, but 150–160 characters is the practical limit before Google cuts it off in the snippet.

The consequence differs by platform, and it's worth knowing which kind you're dealing with. X and most form fields with a maxlength simply block submission — you can't go over. SMS silently splits into extra segments instead of blocking anything. Meta titles and descriptions never error at all; Google just truncates the on-screen snippet, so an overlong description still exists in your page's HTML, it's just not what searchers see.

Emoji, accented characters and some symbols can occupy more than one UTF-16 code unit, which means a naive '.length' check in code (or eyeballing a character count) can disagree with what the platform itself counts. This matters most for X and SMS, where the limit is enforced strictly — testing the actual string against a tool that mirrors the platform's counting method avoids submitting something one character too long.