Adaptive icons on Android 9 with Web App Manifest

Question

I'm setting up an Web App Manifest for my PWA. But the icons for Android get squeezed in a round icon.

I tried normal icon, without background and one considering the safe-zone.

Images of icons installed on my Android

Sadly I don't find any documentation for it and the icon really bugs me.

Edited:

"name": "PWA-Test",
"short_name": "PWA-Test",
"display": "standalone",
"scope": "/",
"start_url": "/", 
"icons": [
    {
        "src": "/assets/android-chrome-36x36.png",
        "sizes": "36x36",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-48x48.png",
        "sizes": "48x48",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-72x72.png",
        "sizes": "72x72",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-96x96.png",
        "sizes": "96x96",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-144x144.png",
        "sizes": "144x144",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-192x192.png",
        "sizes": "192x192",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-256x256.png",
        "sizes": "256x256",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-384x384.png",
        "sizes": "384x384",
        "type": "image/png"
    },
    {
        "src": "/assets/android-chrome-512x512.png",
        "sizes": "512x512",
        "type": "image/png"
    }
],
"theme_color": "#5c3552",
"background_color": "#5c3552"

Edit 2: It seems to work when i just use a round icon. But the UI ist different on every version of Android I guess.

Solved it by making a round icon. The problem now is, the icon on Desktop is now round as well.

Answer 1

I am running my PWAs on Android devices and I did not have to make any special adjustments to the icons.

Here a portion of my web manifest:

"icons": [
     // Other sizes
    {
      "src": "/images/icons-144.png",
      "type": "image/png",
      "sizes": "144x144"
    },    
    {
      "src": "/images/icons-192.png",
      "type": "image/png",
      "sizes": "192x192"
    },
    {
      "src": "/images/icons-512.png",
      "type": "image/png",
      "sizes": "512x512"
    }
  ]

In case of Chrome, it needs two icon sizes 192x192 and 512x512 at least:

Include a 192x192 pixel icon and a 512x512 pixel icon. Chrome will automatically scale the icon for the device. If you'd prefer to scale your own icons and adjust them for pixel-perfection, provide icons in increments of 48dp.

WebAPKs generated in Chrome 71 or later will show a larger icon on the splash screen. No action is required, as long as the recommended icons are provided.

Answer 2

First, you need to create a icon with 2 layers.

You can use this utility: https://maskable.app/editor

After, you need to set purpose maskable in your manifest.json

{
  …
  "icons": [
    …
    {
      "src": "path/to/maskable_icon.png",
      "sizes": "196x196",
      "type": "image/png",
      "purpose": "any maskable" // <-- New property value `"maskable"`
    }
  ]
  …
} 

more information in this article: https://web.dev/maskable-icon/