TikTok Spark Ads specs
Spark Ads promote an existing organic TikTok post instead of an uploaded ad file. TikTok's guide lists .mp4 or .mov, no duration restriction, and a caption taken from the organic post, shown up to four lines including emojis. Engagement on the ad accrues to the original post.
Updated
Spark Ads versus standard in-feed ads
| Spark Ads | Non-Spark in-feed | |
|---|---|---|
| Source | An existing organic post | A file uploaded to Ads Manager |
| File types | .mp4 or .mov | .mp4, .mov, .mpeg, .3gp, .avi |
| Length | No restriction stated | Up to 10 minutes |
| Caption | Taken from the organic post, up to 4 lines | Written in Ads Manager; no links, @ or hashtags |
| Identity | The posting account | A display name and profile photo you set |
Why advertisers choose Spark
A Spark Ad looks exactly like an organic post because it is one. The account name, the caption and the engagement counts belong to the original video, so the ad carries whatever social proof the post has already earned.
That makes Spark Ads a natural fit for creator partnerships. A creator posts on their own account, authorises the post for advertising, and the brand puts spend behind it without re-uploading the file or losing the creator's identity on the ad.
What changes in your workflow
- Publish the video organically, on your account or a creator's.
- Get authorisation for the post to be used in ads (the creator generates it if it is their post).
- Select the authorised post when building the ad instead of uploading a file.
- Write the ad's call to action and landing page in Ads Manager; the caption stays as posted.
Things to check before you boost a post
- The caption cannot be edited per ad, so it must work for paid traffic as written.
- Claims made in the organic post become ad claims once you pay to promote them, and ad policies apply.
- If you plan to test many variants, standard uploads are easier to version than a stream of organic posts.
Questions
- Do Spark Ads have a length limit?
- TikTok's in-feed ads guide lists no duration restriction for Spark Ads, and .mp4 or .mov as the accepted file types.
- Can I edit the caption on a Spark Ad?
- The caption is pulled from the organic post and shown up to four lines including emojis, so change it on the post itself if it needs to differ.
Sources
Read on 13 October 2026. Platforms change specs and policies without notice; check the source before you build to a number.