The Google Play screenshot size
Google Play screenshots are JPEG or 24-bit PNG without transparency, between 320 and 3840 pixels on each side, and the long side can be at most twice the short side. 1080 x 1920 is a common phone size that fits every rule.
How to make a good Google Play screenshot
Show the app's main screens with a short caption above each. Higher resolution screenshots, at least 1080 pixels on the short side, look sharper and are expected for some promotional placements.
Questions
What size is a Google Play screenshot?
Google Play screenshots are JPEG or 24-bit PNG without transparency, between 320 and 3840 pixels on each side, and the long side can be at most twice the short side.
What is the best Google Play screenshot size?
1080 x 1920 for phones in portrait (or 1920 x 1080 in landscape). It sits well within the 320 to 3840 pixel limits and the 2:1 ratio rule.
Is my image uploaded anywhere?
No. The image is read and resized in your browser; nothing is sent to a server.
How does the resize work?
It scales the image to cover the target size and crops the overflow evenly from the edges, so nothing is stretched.