Paste a caption and see at once whether it fits each platform — counted the way each one counts, because an emoji is 1 on Bluesky, 2 on X and 4 on Threads. Everything is counted on this page; nothing is sent.
Characters you see
173
Words
30
Hashtags
3
@mentions · emoji
0 · 1
Fits every platform below.
2,200 characters and 20 @ tags (Graph API). Hashtags: the Help Centre now says up to 5 per post; the API page still says 30.
2,200 for a video caption, counted in UTF-16 (an emoji is 2). Photo posts allow 4,000.
5,000 bytes, the API's unit (an accented letter is 2, an emoji 4), and no < or >. More than 60 hashtags and YouTube ignores them all.
“Posts can contain up to 3,000 characters.”
174 characters — no limit published.
Meta publishes no post length limit.
800 characters for a Pin description (Help Centre and API agree); the title is a separate 100.
280 weighted characters: most letters 1, CJK 2, every emoji 2, every link 23. Premium accounts can post up to 25,000.
300 graphemes (an emoji or flag is 1), and at most 3,000 bytes.
3 hashtags — Threads takes 1 topic tag per post, so only one becomes a tag.
500 characters, each emoji counted as its UTF-8 bytes (4 for most). One topic tag per post.
500 by default (each server can change it), counted in graphemes; every link counts as 23.
Your caption is counted on this page. It isn't saved or sent to CAPTD.
Turn this into a whole campaign
Writing the same post for five platforms? Spotlight's Campaign mode writes one version per platform from one brief, each inside that platform's limit.
Campaign mode is part of the Spotlight workspace on CAPTD's paid plans — see pricing.
Open Campaign modeMeasures one caption against each platform's own limit, in that platform's own unit: UTF-16 characters on Instagram, TikTok and LinkedIn, bytes for a YouTube description, weighted characters on X, graphemes on Bluesky, bytes-per-emoji on Threads, links-as-23 on Mastodon. It also counts hashtags and @mentions where a platform caps them.
The bar is the platform's limit. A card turns red when the caption is over, or when it has more hashtags or @mentions than the platform publishes as its maximum. Facebook shows only a count: Meta publishes no limit.
Every platform stores text a little differently, and that's the unit its limit is in. Instagram and TikTok count UTF-16 code units, so most emoji cost 2. YouTube's description limit is in bytes, so an accented letter costs 2. X weights characters — most letters 1, Chinese or Japanese characters 2, every emoji 2, any link 23.
Bluesky counts graphemes (what you see as one character, so an emoji or a flag is 1) but also caps the post at 3,000 bytes. Threads counts each emoji as its UTF-8 bytes. A plain character count can say a caption fits when the platform says it doesn't.
A caption that's too long is cut, or the post won't publish. Checking all the platforms at once tells you which version needs trimming before you start posting.
Where a platform publishes no limit (Facebook), none is shown. Mastodon's 500 is the default; each server can set its own.
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