Images

Intro

Endpoint: https://api.omnisend.com/api/images

The Images API lets you upload, retrieve, and manage images for your brand.

Upload methods

There are two ways to upload an image:

MethodEndpointContent-Type
File uploadPOST /api/images/uploadmultipart/form-data
URL uploadPOST /api/imagesapplication/json

Both methods accept an optional name parameter. If not provided, the name defaults to the original filename (file upload) or is extracted from the URL path (URL upload).

File requirements

ConstraintValue
Supported formatsJPEG, PNG, GIF, WebP
Max file size5 MB
Format detectionBased on file content, not file extension

Note: Images wider than 2000px are automatically resized. EXIF metadata is stripped from all uploads (except WebP).

URL upload rules

When uploading via URL:

  • The URL must be publicly accessible over HTTP or HTTPS
  • Private IP ranges are blocked (e.g., 10.x.x.x, 172.16.x.x, 192.168.x.x)
  • If the same URL was previously uploaded for your brand, the existing image is returned without re-uploading

Delete behavior

Deleting an image is idempotent — calling DELETE /api/images/{id} for an already-deleted or non-existent image still returns 204 No Content.

Example: Upload image file

curl --request POST \
     --url https://api.omnisend.com/api/images/upload \
     --header 'Authorization: Omnisend-API-Key YOUR_API_KEY' \
     --header 'accept: application/json' \
     --header 'content-type: multipart/form-data' \
     --header 'Omnisend-Version: 2026-03-15' \
     --form 'file=@/Users/user/Documents/logo.png' \
     --form 'name=my-image'

Example: Upload image from URL

curl --request POST \
     --url https://api.omnisend.com/api/images \
     --header 'Authorization: Omnisend-API-Key YOUR_API_KEY' \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --header 'Omnisend-Version: 2026-03-15' \
     --data '{
  "url": "https://example.com/image.jpg",
  "name": "my-image"
}'

The name field is optional. If omitted, the filename is extracted from the URL.

See also