| TikTok | ||
|---|---|---|
| Characters | 10,000 | 2,200 |
| Media | optional | a video (required) |
| Hashtags | none — Reddit has no hashtags | max 5 hashtags, inside the caption (comments are invisible to the algorithm) |
| Links in body | fine | fine |
| Needs platform approval | yes | yes |
Reddit 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.
Reddit allows 10,000 characters; TikTok caps at 2,200. A post written to Reddit's length gets truncated — usually mid-sentence — unless it is rewritten, not trimmed.
Reddit: none — Reddit has no hashtags. 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.
Reddit is value-first; it must read like a community member, not an ad. 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": ["reddit", "tiktok"],
"text": "Your post",
"per_platform": {
"reddit": { "text": "The Reddit 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 Reddit · all combinations · which APIs need approval