Social Media Character Limits 2026: 15 Platforms

These are the text limits OmniFire works with when it publishes to each platform. They come from the code that sends posts to each platform’s API, so they are the numbers a post has to fit in practice. After the table I cover the three things that change once the same post goes to several platforms at the same time.

Character limits by platform (September 2026)

The range runs from 300 on Bluesky to 63,206 on Facebook, a factor of about 200. That spread is the whole problem with cross-posting.

1. The shortest limit decides what the post can say

A caption written for LinkedIn can use 3,000 characters. Bluesky takes 300 of them. If the same text goes to both, one of two things happens: it gets split into several posts, or the end is cut off.

The simplest habit that works: write the core message so it fits in 280 characters first. Then decide whether the longer platforms really need more. Often they don’t, and a short post reads fine on LinkedIn too. When a platform does need a different version, such as a long LinkedIn post or a WeChat article, write it as a separate post.

In OmniFire the text of a regular post is shared by every platform you pick. What differs per platform are the settings that only make sense there, such as YouTube tags, the post language on Bluesky, or who can comment on TikTok.

2. On X, Bluesky and Mastodon a long post becomes a thread

When the text is longer than the limit on X (without Premium), Bluesky or Mastodon, OmniFire publishes it as a chain of replies instead of cutting it. On X the split happens at the end of a sentence where possible, then at a line break, then between words. Bluesky and Mastodon split between words.

The other platforms have no thread format, so the limit is final there. On Instagram, TikTok, YouTube and Discord, anything beyond the limit is cut off when the post goes out. For most platforms the preview in the composer counts characters and turns red past the limit, so check it before you schedule a long caption.

3. Chinese and Japanese text runs out twice as fast on X

X does not count characters the way a text editor does. Latin letters count as 1, while Chinese, Japanese and Korean characters and full-width punctuation count as 2. A tweet in Chinese holds about 140 characters, not 280.

We learned this from a real post. In July a bilingual post looked like 257 characters in the editor, X weighed it at 303 and rejected it. Since then OmniFire measures X text with X’s own weighting, so a post like that is split into a thread before it is sent.

Bluesky works differently: its 300 counts each Chinese character once. The same Chinese sentence can fit on Bluesky and still be too long for a single tweet.

Formats with their own editor

Some content has fields a regular post does not have, so it gets its own editor in OmniFire:

• X Articles (for Premium accounts), with a headline, cover image and formatted body
• WeChat Official Account articles, including several articles sent as one batch
• Bilibili columns
• Long videos for YouTube and Bilibili, with title, description and video settings

Bilibili and WeChat accounts don’t appear in the regular composer for this reason: what they publish has a different shape. All of them can still be scheduled, the same as regular posts.

Keeping the table current

Platforms change their limits now and then, and when they do we change the code that publishes to them. This table follows that code, and each platform page on this site lists the same figures along with the media types and formats OmniFire supports there.