You do not need a huge image resolution for your collection. Unless you have a specific purpose for a massive resolution, try to be conservative. There are many popular NFT collections that have an image size around 1024x1024 or similar. Making a 2k, 4k, 8k image size does not make sense if you are just starting out and you are making a huge generative collection of 10,000 images.
For a reference point, Milady Maker image size is 1000x1250. If you use an irregular size and you plan for your collection to be used as PFPs you should make sure your images crop well on social media platforms.
Generally you should prefer .PNG file format for images. You can still use .JPEG but if you do you should use max quality.
Your collection needs three primary images:
- Hero - The image displayed near the minting UI. The size can be around 512x512 to 1024x1024. Try to keep the size in MB at or below 1MB. Can be PNG or JPEG.
- Icon - The small icon shown when looking at the collection in a list view. Size can be from 128x128 to 512x512. Can be a GIF, PNG, or JPEG. Try to keep size below 1MB. If you are uploading a file larger than 1MB you are doing it wrong.
- Banner - This size can be flexible depending on what you want on it. A generally acceptable size is 1024x256 to 2048x512. Try different sizes along with what you put on your banner to see what looks good for your collection. Reference other collections too. Can be PNG or JPEG.
- Featured BG - If we tell you that we want to feature you we will need an image of the size of 1800x620 this image will be the background of the featured section and a majority of it will be covered up by UI.
Scatter will in general automatically resize images down to reasonable sizes, but you still do not need to upload super massive image sizes.
If you have an NFT collection that uses MP4s it's a good idea to keep each below 10MB. A target of 1MB is better.
Make sure you include both a static image in the image field as well as the link to the video file in the animation_url field.
Interactive NFTs should have images of the same size you want your iframe size to be in general set in the image field and then the animation_url field set to be the interactive NFT link. Good marketplaces will use your image size as a reference for your iframe size and proportions.
High tier Interactive NFTs bundle everything together into a single portable .html file.