Google Post photo requirements

The guidelines for photos that are used in the Google Posts.

The photos used in the Google Posts should follow the Google content policy. It's recommended to use photos that are high quality and to not use heavy filters.

The size requirements are the following: 

Max size: 10000px * 10000px (Not recommended to use very small photos)
Recommended resolution: 720 px tall, 720 px wide
Minimum resolution: 250 px tall, 250 px wide
Weight: 10 KB-5 MB
Ratio: 13:6