Recommended Aspect Ratio for Images in Whatsapp Messages
The recommended aspect ratio is 1.91:1 for uploading an image on the Whatsapp template for optimal resolution. If you don’t use this ratio, the image of the WhatsApp template might show with strange cropping, zooming on WhatsApp.
The recommended aspect ratio for Whatsapp templates is 1.91:1

Here is a sample image link in that aspect ratio that you can download and re-use: https://cdn.live.zoko.io/store/customers/d8aafa81-3470-483f-bdb2-c6466bc8176a-zo-ko-image+template.png
Learn more about Aspect ratios: https://en.wikipedia.org/wiki/Aspect_ratio_(image)
Learn more about Media sizes support on Whatsapp template.
Keywords: Template image ratio, Image resolution.