It is important that your media file complies with the KakaoTalk's criteria, which is defined in the Media Messages section of our KakaoTalk developer documentation:
Media included in the Media message will be rejected by the channel if:
- the width is below 500px, or if the 'width:length' ratio is below 2:1, or above 3:4 or if the image dimension is not equal to [800px * 600px]
- image file format is different than JPG or PNG
- file size is bigger than 500KB or for image with dimension [800px * 600px] is bigger than 2MB.
Double check your image and make sure it's in the right format before resending your FriendTalk message. Here are few examples you can use:
- 500x1000 px, 500x800 px, 500x500 px, 500x400 px
- 600x1200 px, 600x960 px, 600x450 px
- 720x720 px (Recommended!)
- 800x600px (wide image)
The Sinch Developer Documentation site contains comprehensive documentation that illustrates how Sinch supports KakaoTalk through the Conversation API.