Social Media Character Limits and Posting Rules
One table instead of 9 help-centre tabs. Captions run from 280 characters on X (Twitter) to 63,206 on Facebook, and the gap between them is why a post copied across networks usually fails on one of them.
By Tayyab, Founder
Social media character limits differ far more than most people assume: Bluesky allows 300 characters, X allows 280, Threads 500, Pinterest 800, Instagram and TikTok 2,200, LinkedIn 3,000, YouTube 5,000 and Facebook 63,206. Hashtag caps, unique-link caps, image counts, file sizes and video lengths differ too, which is why one caption copied to every network usually fails on at least one of them. Content Drifter publishes the full table and validates every post against it before it reaches the calendar.
Text limits
| Network | Characters | Hashtags | Unique links |
|---|---|---|---|
| 2,200 | 30 | No published cap | |
| TikTok | 2,200 | 5 | No published cap |
| X (Twitter) | 280 | 5 | No published cap |
| 63,206 | 10 | No published cap | |
| 3,000 | 5 | No published cap | |
| Threads | 500 | 5 | 5 |
| YouTube | 5,000 | 15 | No published cap |
| 800 | 5 | No published cap | |
| Bluesky | 300 | 5 | No published cap |
Media limits
Counts and ceilings, not dimensions. For the pixel sizes that actually render well, use the image size guide and the carousel size guide.
| Network | Images per post | Max image | Max video | Video length | Media required |
|---|---|---|---|---|---|
| 10 | 8 MB | 300 MB | 15 min | Yes | |
| TikTok | Video only | n/a | 4 GB | 10 min | Yes |
| X (Twitter) | 4 | 5 MB | 512 MB | 2 min 20 sec | No |
| 10 | 4 MB | 1 GB | 20 min | No | |
| 20 | 10 MB | 200 MB | 30 min | No | |
| Threads | 20 | 8 MB | 100 MB | 5 min | No |
| YouTube | Video only | n/a | 256 GB | 12 hours | Yes |
| 1 | 8 MB | 2 GB | 15 min | Yes | |
| Bluesky | 4 | 2 MB | 100 MB | 1 min | No |
Which formats each network takes
| Network | Article | Carousel | Feed post | Reel | Short | Story |
|---|---|---|---|---|---|---|
| No | Yes | Yes | Yes | No | Yes | |
| TikTok | No | No | Yes | No | No | No |
| X (Twitter) | No | Yes | Yes | No | No | No |
| No | Yes | Yes | Yes | No | Yes | |
| Yes | Yes | Yes | No | No | No | |
| Threads | No | Yes | Yes | No | No | No |
| YouTube | No | No | Yes | No | Yes | No |
| No | No | Yes | No | No | No | |
| Bluesky | No | Yes | Yes | No | No | No |
Word limits, and why none of these are word limits
No network counts words. Every ceiling on this page is a character count, which is why a post can fail validation after you shortened it: you removed words but added a long URL. If you think in words, divide by about 6, one five-letter word plus its space. That rounds down, so treat it as a floor rather than a target.
| Network | Characters | Roughly, in words |
|---|---|---|
| 2,200 | about 370 words | |
| TikTok | 2,200 | about 370 words |
| X (Twitter) | 280 | about 50 words |
| 63,206 | about 10,530 words | |
| 3,000 | about 500 words | |
| Threads | 500 | about 80 words |
| YouTube | 5,000 | about 830 words |
| 800 | about 130 words | |
| Bluesky | 300 | about 50 words |
Worth knowing that the ceiling and the useful length are different numbers. Most feeds cut a post off behind a "see more" long before the character limit, so the first line does the work regardless of how much room you are given. The per-network catches lists where each one truncates.
What this table does not cover
Everything above is an organic post ceiling, because that is what our publisher validates against before a post reaches your calendar. Three adjacent limits get asked about constantly and are deliberately absent:
- Direct messages and connection requests. A different surface with its own ceilings. We do not send DMs, so we have no enforced number to publish and will not quote one second-hand.
- Paid ad copy, headlines and primary text. Ad ceilings differ from organic ones on every network and change with each ad-format release. We publish organically only.
- Bio and profile fields. Also capped, also unrelated to a post. The bio generator handles the writing side of that.
For any of those three, each network's own advertising or developer documentation is the only source worth trusting, because they move without notice.
The per-network catches
The numbers above are the easy part. These are the rules that actually break a scheduled post: what counts toward a limit, where a caption gets truncated in the feed, and what an API rejects outright.
Instagram API requires Business/Creator account. All media must be publicly accessible URLs. @-mentions capped at 20 per caption.
TikTok
Video uploads only, no text-only or image-only posts. Content becomes the caption (2,200-char cap). 9:16 vertical, ~3s-600s, MP4/MOV up to 4 GB.
X (Twitter)
Hashtags count toward the 280-character limit. URLs always count as 23 characters. Emojis count as 2 characters.
Truncates at ~480 characters in feed with "See More" link.
Truncates at ~140 characters in feed. Image recommendation: 1200x627. Multi-image carousels: 2-20 images.
Threads
Strict 500-character limit enforced by API. URLs and emojis count at UTF-8 byte length. Max 5 unique links per post (Dec 2025 enforcement).
YouTube
Video uploads only, no text-only or image-only posts. Title is the first 100 chars of content; full content becomes the description.
Every pin requires an image or video AND a board_id. Pin titles are auto-generated from the first 100 chars of content; descriptions cap at 800.
Bluesky
Strict 300-character limit (grapheme-counted). Images ≤ 2 MB each, max 4 per post. Video: MP4 only, ≤ 100 MB, ≤ 60s; account must have a verified email.
Where these numbers come from
This is not a survey and it is not research. It is the rule table our own publisher validates against before a post is allowed onto the calendar, published here as-is. When an API changes and we update what we enforce, this page changes with it, because it reads the same source rather than a copy of it.
Platforms do change these without announcing them, so treat anything decision-critical as worth confirming against the network's own developer docs. If you find a row that is out of date, tell us and we will correct it. Reuse the table freely with a link back.
Frequently asked questions
What is the character limit for each social media platform?
Bluesky is 300, X is 280, Threads is 500, Pinterest is 800, Instagram and TikTok are 2,200, LinkedIn is 3,000, YouTube descriptions are 5,000 and Facebook is 63,206. The tight ones are the ones that break cross-posting: a caption written for Instagram is seven times longer than Bluesky accepts.
Do hashtags and links count toward the character limit?
On X, yes to both: hashtags count, every URL counts as 23 characters regardless of length, and emoji count as two. Threads counts URLs and emoji at their UTF-8 byte length and caps you at five unique links per post. Most other networks count the caption text as written. This is the detail that turns a post that looked fine in a drafting tool into an API rejection.
Which platforms require an image or video?
Instagram, Pinterest, YouTube and TikTok will not accept a text-only post. X, Facebook, LinkedIn, Threads and Bluesky will. Scheduling a text-only post to a media-required network is one of the most common reasons a queued post fails at publish time rather than at draft time.
How long can a video be on each platform?
Bluesky is the shortest at 60 seconds, X allows 140 seconds, Threads 5 minutes, TikTok 10 minutes, Instagram and Pinterest 15 minutes, LinkedIn 30 minutes, Facebook 20 minutes and YouTube up to 12 hours. File-size ceilings vary just as widely, from 100 MB on Threads to 256 GB on YouTube.
Where does this data come from?
It is the rule table Content Drifter validates every post against before it is allowed onto the calendar, published as-is rather than compiled separately, so it stays in step with what we actually enforce. It is a reference, not original research. Platforms change these rules without announcing them, so confirm anything decision-critical against the network’s own developer documentation.
Or stop checking the table
Content Drifter validates every post against these rules before it reaches the calendar, so a caption that is too long or a video that is too big is caught while you can still fix it, not when the scheduled job fires.
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