| X | TikTok | |
|---|---|---|
| Characters | 280 | 2,200 |
| Media | optional | a video (required) |
| Hashtags | 1-2 hashtags, zero is fine | max 5 hashtags, inside the caption (comments are invisible to the algorithm) |
| Links in body | suppress reach | fine |
| Needs platform approval | yes | yes |
X posts are frequently text-only. TikTok requires a video on every post, so there is no direct equivalent — you have to attach media before this cross-post is even possible.
X caps at 280 characters, TikTok allows 2,200. Posting the short version verbatim wastes the room TikTok gives you to actually explain the thing.
X: 1-2 hashtags, zero is fine. TikTok: max 5 hashtags, inside the caption (comments are invisible to the algorithm). Carrying the tag block across is the single most obvious sign of an automated cross-post.
X penalises links in the body, so posts written for it park the URL elsewhere. On TikTok links in the body are fine — putting it back is free reach.
TikTok requires a separate title (max 150 characters). X has no such field, so there is nothing to copy across — it has to be written.
X is one hook and nothing else — opinionated, conversational, over in a breath. TikTok is hook-first, not SEO-first: the first 80-100 characters decide everything. Those are different jobs, so the same words cannot do both well — and every algorithm here demotes text that obviously was not written for it. The fix is not to skip cross-posting; it is to send a native version to each network.
curl -X POST https://postwire.io/api/post \
-H "Authorization: Bearer $POSTWIRE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"platforms": ["x", "tiktok"],
"text": "Your post",
"per_platform": {
"x": { "text": "The X version" },
"tiktok": { "text": "The TikTok version" }
}
}'
PostWire's /api/generate writes those per-platform versions for you from a single prompt, respecting
every limit in the table above. From an AI agent it is one MCP tool call.
Other pairs: TikTok to X · all combinations · which APIs need approval