Below, you can find required dimensions for extension images and assets on EXT.
<aside> 📏 Recommended Banner Size: 1070 x 320 pixels, 300 ppi; PNG format ’Key Content’ Size: 512 x 320 pixels
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As a best practice, the title and key image elements should fit in the center, ‘Key Content’ area which is 512 x 320 px (see the red rectangle in the images below for illustration). If the key content doesn’t fit within the area of the red rectangle, it may get clipped as window size varies.
Full-width library image
https://lh4.googleusercontent.com/kHv-rV0MQsfzPuFYWiDHmDVGSTvZRx2wufr_is0wUZgO3CDp8otGCKWkCiVIM5ycTn2qZRjCsjw9uj02UKhtkz7fkJVp2DDmMav9LEt2FrnFMv6UDcjgaRY0BK90pRHcDFfCwvDKew87vH7yiKzBbAo
Medium-width library image
https://lh4.googleusercontent.com/9bM9BssvkaskHVYElm95HvNzy-W585OQOKHX-eHN2KIip8HiuopfQn0DYRphUJ4sm8lBGLWKb-dOvH8P7RZWKkViVrVWP7kCyuo2N0b_T2ct6kfTJQpVhSNQ92SoMR8TCU8dyrq-ye7tN712e_lK4NM
Smallest-width library image
https://lh5.googleusercontent.com/gPTe1DFbUwCM8tLpNodNqES-wQREiUkr4ZViPnzYio_YgFMyQcEpBcZX3366f2sxbFYTWMTj-w0cTfbO7Z_hbgENSywHjL3M9_qB3QbmM5yvTVAerriNLasYyvw_ExMqpkVxfSrdfKGulBOay8t_qfc
This is why it’s important that the extension title and key elements are contained within the red rectangle!
Template file
<aside> 📏 Recommended Icon Size: 1024 x 1024 pixels, 300 ppi; PNG format
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There are several places the icon can appear within EXT:
1) Icon in library view
2) Icon in extension settings menu
3) Icon in the sidebar
Template file