Social media character limits for every platform
Character limits are the most-checked and least-explained numbers in social media. The limit itself is easy to look up; what is harder to find is what each platform does when you exceed it, which varies far more than people expect and is usually the thing that ruins a post.
The limits
These are the limits AutoPos.io enforces when scheduling, so they are the same numbers our own publishing checks against:
| Platform | Character limit | Formats |
|---|---|---|
| 2,200 | Photos, Reels, Stories | |
| 63,206 | Pages, Posts, Stories | |
| X / Twitter | 280 | Tweets, Threads |
| 3,000 | Posts, Articles | |
| YouTube | 5,000 | Videos, Shorts, Community |
| TikTok | 2,200 | Videos, Stories |
| 10,000 | Posts, Links, Subreddits |
What happens when you go over
This is where the platforms diverge, and where scheduling tools quietly differ from one another. Three broad behaviours:
- —Hard rejection — the post simply fails. You find out at publish time, which is the worst moment to find out if the post was scheduled for 6am.
- —Silent truncation — the post publishes with the end cut off, often mid-sentence. Nothing errors, so nobody notices until a reader points it out.
- —Threading — the text is split across linked posts. On X this is the expected behaviour for long-form; elsewhere it is not available at all.
The practical consequence is that a caption written for one platform is not automatically safe on another. A 2,000-character LinkedIn post is comfortable there, fits Instagram, and is seven times over the limit on X.
Counting is not as simple as it looks
Emoji, accented characters and non-Latin scripts do not all count as one character in every system. An emoji is frequently two units in a naive count and one character to the platform, so a caption that a text editor calls 285 characters may be perfectly valid on X. Our caption length checker counts by Unicode code point, which matches what the networks report more closely than a raw string length does.
A practical approach
- —Write to the shortest platform you are targeting, then expand for the longer ones rather than trimming down.
- —Put the essential message in the first 125 characters — most platforms truncate the preview long before the hard limit.
- —Check before scheduling, not after publishing. A truncated post cannot be edited on every platform.