Social Media Character Limits Checker

About the Social Media Character Limits Checker

Paste a post, caption, bio, display name, username, title or alt text and see straight away whether it fits on X, Instagram, Threads, Facebook, LinkedIn, TikTok, YouTube, Pinterest, Reddit, Bluesky, Mastodon, Snapchat, Discord, Twitch and Google Business Profile. Every platform is measured the way it counts: X weights links and emoji, Bluesky limits characters and bytes and shortens links, Mastodon counts every link as 23, Threads counts emoji by their UTF-8 size and TikTok’s API counts UTF-16 units.

Under the checker is the full reference table — every limit with a link to its source. Only limits that a platform publishes in its help centre, API documentation, official announcements or open-source code are included. Where a platform does not document a number, it is left out rather than guessed.

Common uses

• Writing one announcement and checking it fits every network you post to before scheduling it.
• Choosing a username or display name that works the same on every platform.
• Checking alt text, video titles and Pin titles against their limits.
• Keeping ad text within the length each ad platform recommends, so it is not cut off.
• Settling “what is the limit, really?” with a link to the platform’s own page.

How each platform counts

• X: a weighted count from X’s open-source twitter-text library: letters, digits and most punctuation count 1; emoji and Chinese, Japanese and Korean characters count 2; every link counts 23, however long. X Premium allows 25,000.
• Bluesky: at most 300 characters as you see them (graphemes) and 3,000 bytes of UTF-8. The Bluesky app shortens long links before saving — https://www.example.com/blog/2024/10/a-long-post becomes www.example.com/blog/2024/10... — and the short form is what counts.
• Mastodon: 500 characters by default (each server can change it). Links that start with http:// or https:// count as 23; in @[email protected] only @alice counts. A content warning counts towards the same 500.
• Threads: 500 characters, with each emoji counted as its UTF-8 size (4 or more), and at most 5 different links.
• TikTok: the documented limits are for its posting API, counted in UTF-16 units — most emoji count 2.
• Google review replies: 4,096 bytes of UTF-8.
• Everything else: characters as you see them, so 👍🏽 or 🇮🇳 counts as 1. Platforms that do not say how they count emoji may count them as more.

Limits that are not listed, and why

Some limits you may be looking for are enforced in the apps but not published anywhere official: Instagram’s bio and username length, LinkedIn’s headline, About and comment lengths, Facebook’s post length, TikTok’s in-app caption and bio, comment lengths on Instagram, YouTube and Reddit, Reddit’s username length, and Google Business Profile posts. The numbers quoted for them online are copied from site to site, and copies go stale: many lists still give Instagram’s old limit of 30 hashtags (even Meta’s API reference still says 30), although Instagram’s help centre says 5. When you need one of these, check it in the app itself.

Where the “more” fold falls

Only a few platforms document where text is cut off in feeds, and the checker marks those: Pinterest says the first 40 characters of a Pin title may show in feeds (30 in Chinese, Japanese, Korean or Arabic), and LinkedIn says ad introductory text up to 150 characters, headlines up to 70 and descriptions up to 100 avoid truncation. YouTube only says viewers see “the first few lines” of a description before Show more, and Instagram, X and LinkedIn do not publish where post text is cut — it depends on the screen width and the line breaks. For a visual preview, use the Instagram Line Break Generator or the LinkedIn Text Formatter.

How these limits were checked

Every number was read from the page linked next to it in the table: help centres, API references, official announcements and, for Bluesky and Mastodon, their open-source code. Where a help centre blocks automated reading (X and TikTok), the Internet Archive copy of the official page was used and is linked too. Mastodon’s numbers come from the current release (4.7.3) and the live settings of mastodon.social, because the documentation still shows older defaults (30-character display names, 25-character poll options). Platforms change limits without notice — if a post is rejected, the platform’s own counter is right.

Limitations

• Platforms change limits without warning. If the app disagrees, trust the app.
• Mastodon servers set their own limits; the checker uses the defaults of Mastodon 4.7 as configured on mastodon.social.
• Links are found with X’s twitter-text rules for X, Threads and Mastodon, and with Bluesky’s own pattern for Bluesky. Links typed without https:// are only recognised when they end in a domain ending from twitter-text’s list.
• A Mastodon content warning counts towards the same 500 characters, but the checker only counts the text in the box.
• Hashtags and @ mentions are counted with simple rules (# or @ followed by letters, digits or underscores); platforms may treat unusual tags differently.

Privacy

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