How to use the Bio Length Checker
- Paste the bio exactly as you would save it. Include line breaks, emoji and any link. A line break counts as a character in the networks that keep it, so the tool counts it too.
- Add the keywords you want to be found for. Type a few words separated by commas. The tool says whether each one appears, whether it sits in the first 40 characters, and which fields would cut it off.
- Read the count and notes for each field. Each row shows used and remaining characters, whether links usually render as links there, and whether line breaks survive.
- Copy the trimmed version where you run over. Over-limit rows offer a cut that ends on a whole sentence when one fits, and on a whole word when none does.
What the bio checker measures, and its sources
What it checks
Your text is counted once for each of eleven profile fields: X, Instagram, TikTok, Threads, LinkedIn headline, LinkedIn About, YouTube channel description, Pinterest, Bluesky, Mastodon and Pixelfed. You get used and remaining characters, a bar showing how full the field is, and an exact overage when you run over.
It also counts emoji (a joined sequence counts as one), links and line breaks, checks the first 40 characters for weak openings, and looks up each keyword you supply with its position. Trimmed suggestions cut at the last full sentence that fits. A full stop inside a web address is not treated as a sentence end. If no sentence fits, it cuts at a word and says so.
Sources
Bluesky: the app.bsky.actor.profile lexicon in the AT Protocol repository. Mastodon: NOTE_LENGTH_LIMIT in app/models/account.rb. Pixelfed: max_bio_length in config/pixelfed.php. Those three were fetched in October 2026. The remaining limits are widely documented, approximate figures. Link and line break notes describe observed app behaviour and are always approximate.
Limitations
Mastodon and Pixelfed servers can change their limits, so your server may differ. Apps count some characters in their own way, and the approximate limits can change without notice. The tool cannot know whether a link in your bio is turned into a tappable one for your account type. A fits result means the numbers work, not that the profile will read well, so read the trimmed version aloud before you save it.
Frequently asked questions
How is this different from the character counter?
The Social Media Character Counter measures posts and captions against post limits. Profile bios use separate, much shorter limits, and several fields behave differently from posts: some drop line breaks, some do not make links tappable. This tool is built for those profile fields. For posts, use the character counter or the grapheme limit checker.
Which bio limits are verified and which are approximate?
Three come from primary sources checked in October 2026: Bluesky's profile lexicon sets 256 graphemes, Mastodon's source code sets 500 characters, and Pixelfed's default configuration sets 125. The X, Instagram, TikTok, LinkedIn, YouTube, Pinterest and Threads figures are widely documented but their help pages could not be fetched, so each is labelled approximate. If an app shows a different counter, trust the app.
Why is Bluesky counted differently?
Bluesky counts graphemes, the visible units a reader sees, so a family emoji built from five code points counts as one. Most other networks count characters in a looser way. The tool counts each field the way that field says, so the same bio can use different totals in different rows.
Do links in a bio work everywhere?
No. Some fields turn a pasted URL into a tappable link and some show it as plain text. The tool marks each field as clickable, plain or varies, based on how the apps are widely reported to behave, and says approximate because this is app behaviour and not a published rule. When a field matters for traffic, test it once on your own profile.
What does the first 40 characters check look for?
Search results, follow suggestions and profile cards often show only the opening of a bio. The check flags greetings and self-introductions that waste that space, openings made only of symbols or several emoji, openings that start with a tag or link, and a 40-character cut that would land mid-word.
Is my bio saved or sent anywhere?
No. Counting and trimming happen in your browser. Nothing is uploaded, and reloading the page clears the box.