Creative formats and limits
The file types, sizes and lengths Koast accepts for images and videos.
This page lists what the creative library accepts and the limits that apply when you turn creatives into ads.
File types
| Kind | Formats you can upload |
|---|---|
| Images | PNG, JPG, GIF, WebP |
| Videos | MP4, MOV |
Anything else is refused with: "Please upload only images (.png, .jpg, .gif, .webp) or videos (.mp4, .mov)". In a folder upload, other files are skipped and Koast lists them.
What each ad platform accepts
Koast checks each file against your ad account's platform when you upload it, so a file that can't run is refused right away instead of failing at launch.
| Check | Meta |
|---|---|
| Image formats | JPG and PNG only |
| Minimum width | None set by Koast |
- A GIF or WebP image on a Meta ad account is refused with a message like "Failed to upload loop.gif: "loop.gif" is a GIF image. Meta accepts JPG and PNG". Re-export it as JPG or PNG and upload it again.
The same checks run again before launch for every creative on every ad, including placement versions.
Upload limits
| Limit | Value |
|---|---|
| One image added with Upload New Creative, or dropped on its own | 10 MB |
| Files in one folder upload or drop | 500 |
| Total size of one folder upload or drop | 2GB |
| One file imported from Dropbox | 1GB |
| One file imported from Frame.io | 100 MB. Larger files are skipped. |
| Generations in one Higgsfield import | 24 |
Koast doesn't set its own limit on video length. The ad platform's own rules still apply.
Limits when you build ads
| Limit | Value |
|---|---|
| Carousel cards | 2 to 10 |
| Carousel cards Instagram shows | The first 5. Koast warns you when a carousel has more. |
| Ads created at once | Depends on your plan. Koast tells you when creatives times variations goes over it. |
| Copy variations per field | 5 headlines, 5 primary texts and 5 descriptions |
Placement versions
A creative can carry versions for three placements. See Placement-specific creatives.
| Placement | Shape |
|---|---|
| Feed | 1:1 |
| Stories/Reels | 9:16 |
| Search Results | 1.91:1 |