TikTok Spark Ads Specs: Video, Caption and Authorization Rules
TikTok Spark Ads specs are loose because the ad is an existing organic post: TikTok says there are no restrictions on video ratio, resolution, file type, duration, bitrate or file size, with a 10 minute maximum on videos that can be sparked. The display name and text come from the post and cannot be edited in Ads Manager, and up to 4 caption lines show, including emojis.
Checked October 2026. Sources are listed at the end of the page.
A Spark Ad promotes a post that already lives on a TikTok account, either your own or another creator's with their authorization. Because TikTok runs the post as it is, the rules work differently from a normal in-feed ad you upload. There is no list of pixel sizes or file types to meet. Instead, the specs are about what the post can be, how long it can run, what the caption can hold and how you get permission to use it. This guide lists those rules from TikTok's own ads help pages, then shows how to make a post that works well as a Spark Ad. Every value below comes from TikTok's help center.
| Spec | TikTok's rule | Notes |
|---|---|---|
| Video ratio and resolution | No restrictions | Applies to organic videos from any TikTok account. |
| File type, bitrate and file size | No restrictions | The post is already on TikTok, so there is no upload to check. |
| Video length | 10 minute maximum | Longer videos cannot be sparked. |
| Ad caption | Can be left blank | Up to 4 lines can be displayed, including emojis. |
| Tags, emoji and hashtags | Allowed in captions | Unlike non-Spark ads, which do not support emoji in the display name. |
| Display name and text | Taken from the organic post | Cannot be edited while you create the ad in Ads Manager. |
| Banned posts | Rejected | A post banned on TikTok is also rejected in Ads Manager. |
| Authorization code length | 7, 30, 60 or 365 days | The creator picks the duration when they generate the code. |
| Codes per batch | Up to 20 at a time | When you authorize posts in a Smart+ campaign. |
| Spark Ads per account | Maximum of 10,000 | Per TikTok Ads Manager account. |
| Private videos | Become public once used | Privacy status cannot be changed during promotion. |
| Deleting a sparked video | Un-authorize it first | Then the creator can delete it from the organic account. |
TikTok Spark Ads Specs: Video, Caption and Authorization Rules
Make the post for the feed, not for an ad slot
Spark Ads have no ratio or resolution rules, but the post still plays in a vertical phone feed. Plan a vertical video so it fills the screen, and keep it under the 10 minute maximum so it can be sparked at all. Shorter is easier to watch to the end.
Keep text and your product clear of the interface
TikTok lays the caption, display name and buttons over the video, and on a Spark Ad the caption can show up to 4 lines. Keep on-screen text and your product near the centre. Check a still frame with the free TikTok Safe Zone Checker before you post.
Write the caption you want the ad to keep
The ad's text comes from the organic post and cannot be edited in Ads Manager, so write the caption as if it were the ad copy from the start. Tags, emoji and hashtags are allowed. Keep the first lines clear, since only up to 4 lines show. TikTok's ad policies still apply, so avoid absolute claims and misleading before-and-after comparisons.
Make or finish the video in Infinall AI
On Pro, the Video tool in Infinall AI lets you pick a platform preset and make a video from 1 to 180 seconds that uses your saved brand. Motion makes short animated videos on Free and Pro and exports an MP4. To trim, caption or compress a clip you already have, the AI Editor exports in your browser with no credits.
Publish the post, then get the code
Post the video to TikTok, from the app or from the Infinall Social Hub calendar, which publishes by itself once the TikTok account is connected (a Pro feature). For a creator's post, the creator opens Ad settings on the video, turns on ad authorization, picks 7, 30, 60 or 365 days and copies the code to you.
Build the Spark Ad in TikTok Ads Manager
In TikTok Ads Manager, add the post from your linked account or enter the creator's video code, then finish the ad settings and publish. Preview the post first in the free TikTok Ad Mockup if you want to see how the caption and button sit over it.
Spark Ads versus normal in-feed ads
A normal auction in-feed ad is a new video you upload to Ads Manager. It has to meet TikTok's file rules: 9:16 at 540 x 960 pixels or more (16:9 and 1:1 are also accepted), .mp4, .mov, .mpeg, .3gp or .avi, 500 MB or less, up to 10 minutes and at least 516 kbps. Its caption is limited to 100 characters with no links, and the display name to 20 characters with no emoji.
A Spark Ad skips those checks because the video is already on TikTok. TikTok's Spark Ads page says views, comments, shares, likes and follows gained while the post is promoted are counted on the organic post. The trade-off is control: you cannot rewrite the display name or text in Ads Manager, so anything you want to change has to be right in the post itself.
Authorization rules to plan around
There are two ways to source a Spark Ad. You can use posts from your own linked TikTok account, or posts from other creators who authorize them for you. For a creator's post, TikTok's steps are:
- The creator allows authorized posts in their privacy settings.
- On the video, they tap the three dots, then Ad settings, and agree to the advertising terms.
- They turn on the Ad authorization toggle and generate a video code.
- They pick the authorization duration of 7, 30, 60 or 365 days and copy the code to the advertiser.
- You paste the code in Ads Manager and confirm the post.
Two more rules matter for planning. A private video becomes public once it is used in a campaign, and its privacy cannot be changed while it is promoted. TikTok also offers an Only show in ads setting, which keeps a promoted post out of the For You Feed, Follow Feed, profile page, search and playlists. Before a sparked video can be deleted, it has to be un-authorized as a Spark Ad.
Where Infinall AI helps and where it does not
Infinall AI makes the creative: video on Pro, motion videos, images, voiceovers and copy from your saved brand, so the logo, colours and tone match your other posts. You can plan and publish the organic TikTok post from the Social Hub calendar. The calendar's own caption box allows up to 2200 characters for TikTok, and the caption is the ad text a Spark Ad will keep, so write the opening lines with care.
Infinall does not buy media for you, and the Infinall docs do not describe a Spark Ads option. Authorize and build the Spark Ad in TikTok Ads Manager. For a standard ad, the New ad composer can run ads on TikTok once your ad account is connected; saving drafts is free and a live ad uses 2 credits a month, while TikTok charges the budget to your ad account. The free plan gives 1,000 credits every month with no card. Pro is $10 for the first month, then $30 a month or $299 a year.
Frequently asked questions
What size should a TikTok Spark Ad video be?
TikTok says there are no restrictions on video ratio or resolution for organic videos used as Spark Ads. A vertical video still fills the phone screen best.
How long can a TikTok Spark Ad be?
There is a 10 minute maximum on videos that can be sparked. TikTok sets no limit on file size or bitrate.
What is the TikTok Spark Ads character limit?
The text comes from the organic post and cannot be edited in Ads Manager. The caption can be left blank, and a maximum of 4 lines can be displayed, including emojis.
Can I use hashtags and emoji in a Spark Ad caption?
Yes. TikTok says account tagging, emoji and hashtags are allowed in Spark Ads captions.
How long does a Spark Ads authorization code last?
The creator chooses 7, 30, 60 or 365 days when they generate the code in the post's Ad settings.
Sources and checks
Every price, rating and number on this page comes from the source pages below, checked October 2026. Prices and plans change often, so confirm on the vendor's own page before you buy.
- TikTok Ads Help: About Spark Ads, checked October 2026
- TikTok Ads Help: How to create Spark Ads for Smart+ Campaigns, checked October 2026
- TikTok Ads Help: Spark Ads in Video Shopping Ads, checked October 2026
- TikTok Ads Help: Auction In-Feed Ads, checked October 2026
- TikTok Ads Help: Reservation In-Feed Ads (Reach and Frequency), checked October 2026
- TikTok Ads Help: TopView, checked October 2026
- TikTok Ads Policy: Misleading and False Content, checked October 2026
- Infinall docs: Platforms, file types and sizes, checked October 2026
- Infinall docs: Length, shape, quality and versions, checked October 2026
- Infinall docs: Export your video, checked October 2026
- Infinall docs: Calendar and posts, checked October 2026
- Infinall docs: Caption limits, checked October 2026
- Infinall docs: Paid ads from the Social Hub, checked October 2026