Social Media Character Counter (X, Threads, Instagram, YouTube, Bluesky and more)
Count a post the way X (CJK characters 2, URLs 23), Threads, Instagram, YouTube title and description (bytes), Bluesky, Mastodon and LINE document it, and see what is left and where the text goes over.
- Runs in your browser with cited reference data
Your text is counted on this page only and is not sent anywhere.
The default is 500 characters; some servers use a different limit.
Result
Over the limit on 1 of 8.
X (formerly Twitter) post
As documentedWithin limit115 / 280 weighted characters 165 left
- Counted with the twitter-text v3 rules: characters up to U+10FF (most Latin letters, common symbols) and some punctuation count 1; all other characters (Chinese, Japanese, Korean, and Vietnamese letters with tone marks such as ạ or ế) and every emoji (combined emoji included) count 2; every URL counts 23 whatever its length. Text is Unicode-normalized (NFC) first.
- URLs without http(s):// or www. (such as example.com) count as plain text here; X may count them as 23. Mentions added automatically to replies and attached media are not counted. The standard 280 limit is used.
Sources: X Developer Platform — Counting characters(opens in a new tab) · twitter-text — config v3.json(opens in a new tab) (Checked 2026-11-06)
Threads post
ReferenceWithin limit133 / 500 characters (emoji count as UTF-8 bytes) 367 left
- Links (same URL counted once): 1 / 5 OK
- The Threads API documents a 500-character limit and counts emoji by their UTF-8 bytes. How other characters are counted is not published, so this is a reference value counted in code points.
- Up to 5 links per post (the same URL counts once).
Sources: Meta for Developers — Threads API: posts(opens in a new tab) (Checked 2026-11-06)
Instagram caption
ReferenceWithin limit129 / 2,200 characters (code points) 2,071 left
- Hashtags: 2 / 5 OK
- @mentions: 0 / 20 OK
- Captions are limited to 2,200 characters (Instagram API). The counting unit is not published, so this is a reference value counted in code points.
- The Help Center allows up to 5 hashtags per post (the API reference still says 30) and the API allows up to 20 @mentions.
Sources: Meta for Developers — Instagram API: IG User Media (caption)(opens in a new tab) · Instagram Help Center — Use hashtags on Instagram(opens in a new tab) (Checked 2026-11-06)
YouTube video title
ReferenceOver limit129 / 100 characters (code points) 29 over
- Number of < and >: 0 (not allowed) OK
Goes over the limit from character 100: …ucts.com/en/transport/ ↵ #tr…
- The limit is 100 characters (YouTube Data API). The counting unit is not published, so this is a reference value counted in code points.
- The characters < and > are not allowed.
Sources: YouTube Data API — Videos resource (snippet.title, snippet.description)(opens in a new tab) (Checked 2026-11-06)
YouTube video description
As documentedWithin limit133 / 5,000 bytes (UTF-8) 4,867 left
- Number of < and >: 0 (not allowed) OK
- The limit is 5,000 bytes (YouTube Data API). In UTF-8 most Chinese and Japanese characters take 3 bytes and emoji take 4 bytes or more.
- The characters < and > are not allowed.
Sources: YouTube Data API — Videos resource (snippet.title, snippet.description)(opens in a new tab) (Checked 2026-11-06)
Bluesky post
As documentedWithin limit128 / 300 graphemes (visible characters) 172 left
133 / 3,000 bytes (UTF-8) 2,867 left
- The post text must stay within 300 graphemes (visible characters) and 3,000 bytes (UTF-8), as defined in the AT Protocol lexicon.
- URLs count at their full typed length.
Sources: Bluesky @atproto/api — app.bsky.feed.post lexicon(opens in a new tab) · AT Protocol — Lexicon specification (string length units)(opens in a new tab) (Checked 2026-11-06)
Mastodon post
As documentedWithin limit114 / 500 characters (links count as 23) 386 left
- Counted with the same rules as Mastodon itself: grapheme clusters, every link starting with http(s):// counts 23, and a mention like @user@example.com counts only @user.
- Content warning text also counts toward the total. Servers can use a different limit, so you can change it above.
Sources: Mastodon documentation — Posting(opens in a new tab) · Mastodon documentation — Instance (configuration.statuses)(opens in a new tab) · Mastodon source — StatusLengthValidator(opens in a new tab) (Checked 2026-11-06)
LINE text message (Messaging API)
As documentedWithin limit129 / 5,000 characters (UTF-16 code units) 4,871 left
- The 5,000-character limit for text messages sent through the Messaging API (for example by LINE Official Accounts), counted in UTF-16 code units (🍎 counts 2).
- This is not the limit for personal chats. LINE emoji are counted after being replaced by their alternative text, so the count can be higher.
Sources: LINE Developers — Counting text characters (Messaging API)(opens in a new tab) · LINE Developers — Messaging API reference: text message(opens in a new tab) (Checked 2026-11-06)
How to use
- Type or paste your post (a sample text is filled in to start).
- For each service you see the count in its own unit, the limit and what is left or over. When the text is too long, the point where it goes over is shown.
- Change the Mastodon limit to match your server. "Reference" marks services that do not publish how characters are counted.
FAQ
How many Japanese or Chinese characters fit in an X post?
X uses weighted counting: Chinese, Japanese and Korean characters count 2 each, so text in those scripts alone fits 140 characters. Every URL counts 23 whatever its length.
Why is my YouTube description too long when it has fewer than 5,000 characters?
The YouTube Data API limit is 5,000 bytes in UTF-8. Most Chinese and Japanese characters take 3 bytes, and Vietnamese letters with diacritics usually take 2 or 3 bytes.
What does "Reference" mean?
The service publishes a limit but not what counts as one character. The value shown is an estimate counted in code points or a similar unit.
Notes & limitations
- What you enter is processed only on this page and is not sent to YUCTS servers.
- Calculated from each service’s official documentation (checked 2026-11-06); it does not guarantee that a post will go through. Rules can change without notice.
- Facebook is not included because no official character limit could be confirmed. The LINE limit is for text messages sent through the Messaging API, not for personal chats.
- X is counted with the standard 280 limit, and URLs that do not start with http(s):// or www. (such as example.com) count as plain text.
- Emoji and combined characters are split with the browser’s Intl.Segmenter; older browsers without it use a simplified method.
Data sources
- X Developer Platform — Counting characters(opens in a new tab) — Checked on: 2026-11-06
- twitter-text — config v3.json(opens in a new tab) (v3) — Checked on: 2026-11-06
- Meta for Developers — Threads API: posts(opens in a new tab) — Checked on: 2026-11-06
- Meta for Developers — Instagram API: IG User Media (caption)(opens in a new tab) — Checked on: 2026-11-06
- Instagram Help Center — Use hashtags on Instagram(opens in a new tab) — Checked on: 2026-11-06
- YouTube Data API — Videos resource (snippet.title, snippet.description)(opens in a new tab) (last updated 2026-11-03) — Checked on: 2026-11-06
- Bluesky @atproto/api — app.bsky.feed.post lexicon(opens in a new tab) (@atproto/api 0.30.3) — Checked on: 2026-11-06
- AT Protocol — Lexicon specification (string length units)(opens in a new tab) — Checked on: 2026-11-06
- Mastodon documentation — Posting(opens in a new tab) — Checked on: 2026-11-06
- Mastodon documentation — Instance (configuration.statuses)(opens in a new tab) — Checked on: 2026-11-06
- Mastodon source — StatusLengthValidator(opens in a new tab) — Checked on: 2026-11-06
- LINE Developers — Counting text characters (Messaging API)(opens in a new tab) — Checked on: 2026-11-06
- LINE Developers — Messaging API reference: text message(opens in a new tab) — Checked on: 2026-11-06
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