What reaches both
2 kinds of post reach both Instagram and TikTok:
| You upload | On Instagram | On TikTok |
|---|---|---|
| Reel / Short video — one vertical video | Published as an Instagram Reel. | Posted as a TikTok video. |
| Social photo post — a photo with a caption | Posted as a photo on your Instagram feed. | Posted as a TikTok photo. |
What does not carry across
Worth knowing before you plan a batch — these are limits of the networks, not of the tool:
- Product reaches Instagram but not TikTok.
Limits worth knowing first
- Instagram: Publishing goes through a Facebook Page — an Instagram professional account has to be linked to one. Reels are not live until Instagram finishes transcoding, which can take several minutes.
- TikTok: A video arrives in your TikTok drafts and you tap Post in the app to publish it — TikTok's draft API carries no caption, so the text is written in the app.
Connecting the two accounts
- Instagram connects with one click, through its own login screen.
- TikTok connects with one click, through its own login screen.
Both connect once and stay connected; if a network expires its own token, the account is paused and you are emailed to reconnect it rather than left with posts silently failing.
How it works
- Connect Instagram and TikTok in Integrations.
- Upload your vertical video or photo once and pick both as targets.
- Let the AI write a caption per network, or write your own.
- Publish now, or schedule it. Each delivery is tracked separately.
Frequently asked questions
Can I post to Instagram and TikTok at the same time?
Yes. reel / short video and social photo post posts reach both Instagram and TikTok from a single upload — you choose both as targets and publish once.
Does the caption have to be identical on Instagram and TikTok?
No. SOSPosting writes a separate, native caption for each network — the length, tone and hashtags that suit Instagram are not the ones that suit TikTok. You can edit either before publishing, or write both yourself.
What can I not send to both?
A product post reaches Instagram but not TikTok. Those are limits of the networks themselves, not of the tool.
What happens if one of them fails?
Each network is delivered independently, so one failing does not block the other. A delivery that fails for good is refunded automatically — you are not charged tokens for a post that never went out.
See every combination on the cross-posting index, or read the setup guides for Instagram and TikTok.