The limits at a glance
| Network | Field | Limit |
|---|---|---|
| Caption | 2,200 characters | |
| Post | 63,206 characters | |
| TikTok | Caption | 4,000 characters |
| YouTube | Title | 100 characters |
| YouTube | Description | 5,000 characters |
| Post | 3,000 characters | |
| Threads | Post | 500 characters |
| Bluesky | Post | 300 characters |
| Pin title | 100 characters | |
| Pin description | 500 characters | |
| X | Post (standard account) | 280 characters |
These are the published limits at the time of writing. Networks change them without much notice, so treat the table as a starting point and check anything you are about to build a process around.
The limit is not the length to aim for
A limit is a ceiling. What a reader actually sees is much shorter: Instagram and Facebook both fold a caption after the first line or two, and a YouTube title is cut off in search results well before 100 characters. On every network the opening words do the work, and the remaining allowance is for detail that a reader who is already interested will expand.
Why one caption cannot go everywhere
The spread is the real problem. A 1,500-character Instagram caption is five times too long for Bluesky and three times too long for Threads. Trimming it to the shortest limit wastes the room the longer networks give you, and pasting it unchanged gets it cut mid-sentence. The conventions differ too: a block of hashtags that is normal on Instagram looks out of place on LinkedIn.
That leaves two honest options: write each caption by hand, or have them written per network. SOSPosting does the second. One upload produces a separate caption for each network you tick, sized to that network's limit, and the review screen shows a live count against the limit for each one before anything is published. It publishes to eight of the nine networks in the table. X is the one it does not.
For the wider picture see the cross-posting guide, and for image counts rather than characters, the carousel guide.
Frequently asked questions
What is the Instagram caption character limit?
An Instagram caption can be up to 2,200 characters. Only the first line or two shows before the reader has to tap more, so the opening words carry the post.
What is the shortest character limit among the major networks?
X at 280 characters for standard accounts, then Bluesky at 300 and Threads at 500.
What is the YouTube title character limit?
A YouTube title can be up to 100 characters and a description up to 5,000. This applies to Shorts as well as long videos.
Does SOSPosting cut my caption if it is too long?
It writes a separate caption for each network to fit that network's limit. When you review a post before publishing, each caption shows a live character count against its limit and flags anything over, so nothing is silently shortened.