How to read this
These are the limits Antwork checks a post against before it goes out. A draft that exceeds one is refused at publish time rather than silently truncated, so it is worth knowing the ceiling before you write to it.
platform-rules.json, the same file create_post, the publishers and the MCP server read, so it cannot drift from what is enforced.Enforced, not advisory
Character limits and media requirements are hard: create_post returns characterCount and characterLimit, and refuses to publish when a post is over. Sizes and durations are checked before upload. Resolutions and aspect ratios are what the platform prefers, and are not refused.
X (Twitter)
280 charsThe tightest text limit of any platform here, and the only one that counts characters by weight rather than by code point.
Text
- 280 characters
- Counted by weight: Latin text and punctuation cost 1, CJK, Arabic, Cyrillic and emoji cost 2, and every URL bills a flat 23 whatever its length.
Media
| Type | Accepted |
|---|---|
| Image | 4 per post · .jpg, .jpeg, .png, .webp · 5 MB · up to 1920x1080 · 16:9 / 1:1 |
| GIF | 1 per post · .gif · 15 MB · up to 1920x1080 · 16:9 / 1:1 |
| Video | 1 per post · .mp4, .mov · 512 MB · up to 1920x1080 · 2 min 20s max · 16:9 / 1:1 |
| Document | 1 per post · .pdf · 100 MB |
- 4 media items per post in total
- Images and video cannot be mixed in one post
The only platform that takes a document, and the only one that lets a document sit beside other media in the same post.
Text
- 3000 characters
Media
| Type | Accepted |
|---|---|
| Image | 9 per post · .jpg, .jpeg, .png, .gif · 5 MB · up to 1920x1080 |
| Video | 1 per post · .mp4 · 5 GB · up to 4096x2304 · 30 min max |
| Document | 1 per post · .pdf · 100 MB |
- 9 media items per post in total
- Images and video cannot be mixed in one post
- A document can sit beside other media
More text room than every other platform combined, and the smallest image ceiling of any of them.
Text
- 63206 characters
Media
| Type | Accepted |
|---|---|
| Image | 10 per post · .jpg, .jpeg, .png, .gif, .webp, .bmp · 4 MB · up to 1200x630 |
| Video | 1 per post · .mp4, .mov, .avi, .wmv, .flv, .webm, .mkv, .m4v, .3gp · 1 GB · 20 min max |
- 10 media items per post in total
- Images and video cannot be mixed in one post
Threads
500 charsTwenty items in one post, more than anywhere else, on a 500 character limit.
Text
- 500 characters
Media
| Type | Accepted |
|---|---|
| Image | 20 per post · .jpg, .jpeg, .png · 8 MB · up to 1080x1080 · 1:1 / 4:5 / 1.91:1 |
| Video | 20 per post · .mp4, .mov · 1 GB · up to 1080x1920 · 5 min max · 9:16 / 1:1 / 4:5 |
- 20 media items per post in total
- Images and video can share one post
Media is mandatory, and image and video can share a single carousel.
Text
- 2200 characters
Media
| Type | Accepted |
|---|---|
| Image | 10 per post · .jpg, .jpeg · 8 MB · up to 1440x1440 · 4:5 / 1:1 / 1.91:1 |
| Video | 10 per post · .mp4 · 300 MB · up to 1080x1920 · 15 min max · 9:16 / 1:1 / 4:5 |
- 10 media items per post in total
- Images and video can share one post
- A video is required — text alone will not publish
YouTube Shorts
5000 charsAntwork posts to Shorts. The duration ceiling is a classification boundary rather than an upload limit: a longer video still uploads, it is simply not categorised as a Short.
Text
- 5000 characters
- The first 100 characters of the body silently become the video title.
Media
| Type | Accepted |
|---|---|
| Video | 1 per post · .mp4, .mov, .avi, .wmv, .flv, .webm, .mkv, .m4v, .3gp · 256 GB · up to 1080x1920 · 3 min max · 9:16 |
- 1 media items per post in total
- Images and video cannot be mixed in one post
- A video is required — text alone will not publish
TikTok
2200 charsOne video per post, and text alone will not publish.
Text
- 2200 characters
Media
| Type | Accepted |
|---|---|
| Video | 1 per post · .mp4, .mov, .mpeg, .3gp, .avi · 4 GB · up to 4096x4096 · 10 min max · 9:16 / 16:9 / 1:1 |
- 1 media items per post in total
- Images and video cannot be mixed in one post
- A video is required — text alone will not publish
One image or video per pin, and the only platform with a minimum resolution rather than just a maximum.
Text
- 800 characters
Media
| Type | Accepted |
|---|---|
| Image | 1 per post · .jpg, .jpeg, .png · 32 MB · up to 1000x1500 · 2:3 |
| Video | 1 per post · .mp4, .mov · 2 GB · up to 1080x1920 · 15 min max · 9:16 |
- 1 media items per post in total
- Images and video cannot be mixed in one post
- A video is required — text alone will not publish
Contact
Spotted a limit that looks wrong? Tell us and we will check it against the platform.