Short answer
AI video works well for paid ads on Instagram Reels and TikTok, and for short demo videos on a TikTok Shop product listing. It is a poor fit for TikTok Shop’s shoppable promo videos, which TikTok expects to be filmed in the real world with a person and the physical product. Every spec below comes from the platforms’ own help pages, opened on 1 November 2026, with links. Specs change often, so re-check them before a big campaign.
If you make AI video for TikTok or Instagram, you will find a dozen “video size” guides that disagree with each other. This one sticks to the platform pages, then covers the part the spec guides skip: which placements suit an AI-generated video.
Instagram Reels ads
From Meta’s Instagram Reels video ad specs (opened 1 November 2026; the page shows no date):
| Item | Meta’s spec |
|---|---|
| Aspect ratio | 9:16 |
| Recommended resolution | 1440 x 2560 pixels |
| File types | MP4, MOV |
| Maximum file size | 4 GB |
| Duration | 0 seconds to 15 minutes |
| Minimum width | 250 px (under 30 seconds), 500 px (30 seconds or longer) |
| Video settings | H.264, fixed frame rate, progressive scan; stereo AAC audio at 128 kbps or higher |
| Safe zones | Keep at least 14% of the top, 35% of the bottom and 6% of each side free of text, logos and key elements |
| Sound and captions | Sound optional but strongly recommended; captions optional but recommended |
Two takeaways. Length is not the constraint: a 15-second ad is well inside the limit. The safe zone is. The bottom 35% is where the caption and call-to-action buttons sit, so keep your text and product in the middle of the frame. And Meta recommends sound, so a video with voiceover and music suits the placement.
TikTok in-feed ads
From TikTok’s auction in-feed ad specs (last updated June 2026, opened 1 November 2026):
| Item | TikTok’s spec for non-Spark ads |
|---|---|
| Aspect ratio and minimum size | 9:16 at 540 x 960 (recommended); 1:1 at 640 x 640; 16:9 at 960 x 540 |
| File types | .mp4, .mov, .mpeg, .3gp, .avi |
| Duration | Up to 10 minutes; no minimum or recommended length given |
| File size | 500 MB or less |
| Bitrate | 516 kbps or more |
| Captions | White, uniform font; no clickable links, “@” symbols or hashtags |
TikTok’s page says nothing about the best length, so treat any “ideal length” in a spec guide as the author’s opinion. Test 15, 20 and 30 seconds against your own results.
TikTok Shop: what the rules mean for AI video
TikTok Shop has two different things people call “video”.
The video on a product listing. TikTok Shop’s guide to adding products (US, dated 24 July 2026) asks for an aspect ratio between 9:16 and 16:9 and a file of at most 100 MB, in MP4, MOV, MKV or AVI. It sets no duration limit and recommends a video that shows one or two selling points. A short AI product demo fits this slot.
Promotional videos linked to products. TikTok Shop’s requirements for high-quality videos and LIVEs (dated 26 October 2026) are stricter:
- Videos should be recorded in a real-world environment, with some camera movement, and feature people, with at least 3 seconds of dynamic content.
- Don’t use still, looping or scrolling images for the whole video.
- Videos should feature the seller’s face and the physical product.
- The page’s rule against AI-generated voices is written for LIVEs; it doesn’t state one for videos.
In plain terms: TikTok Shop is built around creators showing real products. A fully AI-generated clip with no real person or real product footage is a poor match for shoppable promo videos, and we won’t promise otherwise. Check the current rule text, or ask your TikTok Shop contact if you’re unsure.
Where AI video does fit
- Paid ads on Reels and TikTok. The specs above are format limits, not content rules. This is the best fit for a per-minute tool: many short 9:16 variants of one product.
- Listing and product page videos. Short demos of one or two selling points, within the size limits above. The same approach works for Shopify product videos.
- Concept testing. Five 15-second hooks cost about $3.75 at $3 a minute. Run the winners as ads, and film a real creator for TikTok Shop promos.
Whatever you make, put it through a client approval workflow before it goes live, and disclose AI use where each platform’s current policy requires it.
What it costs
On Fabeo’s pricing page, the rate is $3 per rendered minute; the Agency plan works out at about $2.60 ($39 for 15 minutes). Unused minutes carry over to the next month.
| Job | Rendered time | At $3/min | At $2.60/min |
|---|---|---|---|
| One 15-second ad | 0.25 min | $0.75 | $0.65 |
| One 30-second ad | 0.5 min | $1.50 | $1.30 |
| 20 hook variants, 15 seconds each | 5 min | $15.00 | $13.00 |
Regenerating a scene uses rendered minutes too, so budget a few extra for revisions. Try your own numbers in the AI video cost calculator.
Making the files for each platform
Fabeo exports 9:16 for Reels and TikTok, 1:1 for feed and 16:9 for YouTube, and every video comes with a voiceover and background music. Download the finished video and upload it yourself in Meta Ads Manager, TikTok Ads Manager or Seller Center: Fabeo doesn’t connect directly to these platforms. When you write the script, keep text and the product out of the Reels safe zones above. See AI social ads and AI UGC ads for examples, or start from a template.
Checklist
- Pick the placement first: ad, listing video or shoppable promo.
- Take the spec from the platform’s own page, with the date, not from a roundup.
- Make 9:16, and keep key content out of the top 14% and bottom 35% for Reels.
- Test several hooks at 15 seconds, then lengthen only what works.
- For TikTok Shop promos, plan real footage with a person and the product.
FAQ
Can I use AI video on TikTok Shop?
On product listings, yes: a short demo within TikTok’s size and format limits. For shoppable promo videos, TikTok’s quality rules ask for real-world footage featuring a person and the physical product, so a fully AI-generated clip is a poor fit.
What size should a Reels ad be?
9:16, with 1440 x 2560 recommended by Meta. Keep the top 14%, bottom 35% and 6% on each side clear of text and key elements.
How long should a TikTok ad be?
TikTok allows up to 10 minutes and gives no recommended length. Start with 15-second hooks and lengthen the ones that perform.
What does a 15-second AI ad cost on Fabeo?
About $0.75 at $3 per rendered minute, or about $0.65 on the Agency plan, before retakes.
Next step
Work out your monthly minutes with the cost calculator, then compare plans on the pricing page.