Icons

To integrate the icon details into the Progressive Web App (PWA) manifest file, ensure that each icon listed is accompanied by its respective size. For example, icon-256x256.png is indicated as having a size of 256px by 256px. This is crucial for providing clear visual elements across different devices and resolutions.

The sizes attribute indicates the size of the icon to the browser. For PNG or JPEG icons, specify the dimensions (e.g., 48, 96, 256). For vector icons, you can use "any" as they are scalable without losing quality. The format attribute is also important as it tells the browser what the file format is, helping it to render the image correctly or the browser to select the most suitable format.

/config/packages/pwa.yaml

pwa:
    manifest:
        enabled: true
        icons:
            - src: "icons/icon-192x192.png"
              sizes: [192]
            - src: "icons/icon-192x192.png"
              sizes: [192]
              purpose: "maskable"
            - src: "icons/icon.svg"
              sizes: 0

src Parameter

The src parameter is the path to the resource file. It can be an Asset Mapper resource, a relative path or an absolute path to the resource.

/config/packages/pwa.yaml

pwa:
    manifest:
        icons:
            - src: "icons/icon-48x48.png"
              sizes: [48]
            - src: "/home/project/foo/bar/icon-48x48.png"
              sizes: [48]
            - src: "src/resources/data/icon-48x48.png"
              sizes: [48]

sizes Parameter

The sizes parameter indicates the suitable sizes for the icon. The expected value is an positive integer or a list of positive integers.

0 means any size and is suitable only for vector images.

The recommended sizes for application icons are as 48, 72, 96, 144, 168, 192, 256 and 512 pixels.

/config/packages/pwa.yaml

pwa:
    manifest:
        icons:
            - src: "icons/icon-192x192.png"
              sizes: [48, 96, 192]
            - src: "icons/icon.svg"
              sizes: 0

format Parameter

The format parameter corresponds to the mime type of the icon.

If this value is omitted and the component symfony/mime is present, the bundle will guess the correct type.

In general, browsers can read image/png and image/jpg types. Modern browsers may support image/webp.

purpose Parameter

The purpose maskable icons indicates the icon has a security margin and borders can be cropped on certain devices.

Maskable image safe area