A lot of writing has a hard character limit: a post on X, an SMS message, a meta description for SEO, a title tag. This tool counts characters live as you type, so you can see exactly where you stand against a limit instead of guessing or pasting into a platform to find out.
The main character count includes spaces, matching how most platforms (like X or SMS) count characters. A separate "Characters (no spaces)" stat is also shown below it.
Most search engines display up to roughly 155 to 160 characters before truncating, so that's a reasonable target to aim under.
It counts raw characters accurately. Keep in mind X has its own specific counting rules for links and attachments, so for posts near the limit, X's own composer is the final word.