Supported Image Formats
JPG / JPEG
PNG
BMP
GIF
Additional Format (API-Only Support)
The following format is supported exclusively via the Custom Integrations API and is not available through the web app:
WEBP (.webp)
Supported Video Formats
MP4
AVI
MOV
WMV
MKV
File Size Limits
Images: up to 3 MB per file
Videos: up to 3 MB per file
Optimal Creative Dimensions for the GoKart Out-of-the-Box Offerwall (URL / Iframe Integrations)
If you are using GoKart’s default offerwall design through a URL or iframe integration, creatives will display best when uploaded in a 16:9 aspect ratio. While GoKart accepts any resolution, maintaining this ratio ensures that images render cleanly in the out-of-the-box layout without stretching, cropping, or distortion.
Recommended 16:9 Creative Resolutions
256×144 (144p)
320×180 (180p)
426×240 (240p)
640×360 (360p, nHD)
854×480 (480p, WVGA)
1024×576 (576p)
1280×720 (720p, HD)
1366×768 (HD+, common laptop size)
1600×900 (HD+)
1920×1080 (1080p, Full HD)
Using a 16:9 ratio ensures optimal alignment with the built-in card layout, responsive scaling, and cross-device consistency on the standard GoKart offerwall.
Creatives in the API
When creatives are uploaded to an offer, their order in the API response is determined by the upload order in the GoKart UI.
Creatives are returned as an array, and each item includes an order field. This field reflects the sequence in which the creative was uploaded and can be used in your integration logic to decide which asset to display in each placement or view.
Example mapping
You may choose to map creatives by order, for example:
order: 0→ 1:1 image (list view)order: 1→ 16:9 image (featured placement)order: 2→ video (details page)
To ensure consistent behavior, upload creatives in the same sequence that your application expects to consume them.
Mapping Recommendations
Use the order field from the API response to map creatives to specific placements in your UI. Do not rely on file names or URLs.
Sample API response
{
"creatives": [
{ "order": 0, "url": "https://...", "metadata": "" },
{ "order": 1, "url": "https://...", "metadata": "" },
{ "order": 2, "url": "https://...", "metadata": "" }
]
}