maskable icons, sometimes referred to as adaptive icons on Android, you'll also need to add "purpose": "any maskable"
to the icon
property.
For Chrome, you must provide at least a 192x192 pixel icon, and a 512x512 pixel icon. If only those two icon sizes are provided, Chrome will automatically scale the icons to fit the device. If you'd prefer to scale your own icons, and adjust them for pixel-perfection, provide icons in increments of 48dp.
start_url
#The start_url
is required and tells the browser where your application should start when it is launched, and prevents the app from starting on whatever page the user was on when they added your app to their home screen.
Your start_url
should direct the user straight into your app, rather than a product landing page. Think about what the user will want to do once they open your app, and place them there.
background_color
#The background_color
property is used on the splash screen when the application is first launched on mobile.
display
#You can customize what browser UI is shown when your app is launched. For example, you can hide the address bar and browser chrome. Games can even be made to launch full screen.
Property | Use |
---|---|
fullscreen | Opens the web application without any browser UI and takes up the entirety of the available display area. |
standalone | Opens the web app to look and feel like a standalone app. The app runs in its own window, separate from the browser, and hides standard browser UI elements like the URL bar.![]() |
minimal-ui | This mode is similar to standalone , but provides the user a minimal set of UI elements for controlling navigation (such as back and reload).![]() |
browser | A standard browser experience. |
display_override
#Web apps can choose how they are displayed by setting a display
mode in their manifest as explained above. Browsers are not required to support all display modes, but they are required to support the spec-defined fallback chain ("fullscreen"
→ "standalone"
→ "minimal-ui"
→ "browser"
). If they don't support a given mode, they fall back to the next display mode in the chain. This inflexible behavior can be problematic in rare cases, for example, a developer cannot request "minimal-ui"
without being forced back into the "browser"
display mode when "minimal-ui"
is not supported. Another problem is that the current behavior makes it impossible to introduce new display modes in a backward compatible way, since explorations like tabbed application mode don't have a natural place in the fallback chain.
These problems are solved by the display_override
property, which the browser considers before the display
property. Its value is a sequence of strings that are considered in the listed order, and the first supported display mode is applied. If none are supported, the browser falls back to evaluating the display
field.
In the example below, the display mode fallback chain would be as follows. (The details of "window-control-overlay"
are out-of-scope for this article.)
"window-control-overlay"
(First, look at display_override
.)"minimal-ui"
"standalone"
(When display_override
is exhausted, evaluate display
.)"minimal-ui"
(Finally, use the display
fallback chain.)"browser"
{
"display_override": ["window-control-overlay", "minimal-ui"],
"display": "standalone",
}
The browser will not consider display_override
unless display
is also present.
scope
#The scope
defines the set of URLs that the browser considers to be within your app, and is used to decide when the user has left the app. The scope
controls the URL structure that encompasses all the entry and exit points in your web app. Your start_url
must reside within the scope
.
Caution: If the user clicks a link in your app that navigates outside of the scope
, the link will open and render within the existing PWA window. If you want the link to open in a browser tab, you must add target="_blank"
to the <a>
tag. On Android, links with target="_blank"
will open in a Chrome Custom Tab.
A few other notes on scope
:
scope
in your manifest, then the default implied scope
is the directory that your web app manifest is served from.scope
attribute can be a relative path (../
), or any higher level path (/
) which would allow for an increase in coverage of navigations in your web app.start_url
must be in the scope.start_url
is relative to the path defined in the scope
attribute.start_url
starting with /
will always be the root of the origin.theme_color
#The theme_color
sets the color of the tool bar, and may be reflected in the app's preview in task switchers. The theme_color
should match the meta
theme color specified in your document head.
shortcuts
#The shortcuts
property is an array of app shortcut objects whose goal is to provide quick access to key tasks within your app. Each member is a dictionary that contains at least a name
and a url
.
description
#The description
property describes the purpose of your app.
screenshots
#The screenshots
property is an array of image objects, representing your app in common usage scenarios. Each object must include the src
, a sizes
property, and the type
of image.
In Chrome, the image must respond to certain criteria:
The description
and screenshots
properties are currently used only in Chrome for Android when a user wants to install your app. The experimental flag chrome://flags/#mobile-pwa-install-use-bottom-sheet
flag must be enabled in Chrome 90.
After creating the manifest, add a <link>
tag to all the pages of your Progressive Web App. For example:
<link rel="manifest" href="/manifest.json">
The request for the manifest is made without credentials (even if it's on the same domain), thus if the manifest requires credentials, you must include crossorigin="use-credentials"
in the manifest tag.
To verify your manifest is setup correctly, use the Manifest pane in the Application panel of Chrome DevTools.
This pane provides a human-readable version of many of your manifest's properties, and makes it easy to verify that all of the images are loading properly.
When your app first launches on mobile, it can take a moment for the browser to spin up, and the initial content to begin rendering. Instead of showing a white screen that may look to the user like the app is stalled, the browser will show a splash screen until the first paint.
Chrome automatically creates the splash screen from the manifest properties, specifically:
name
background_color
icons
The background_color
should be the same color as the load page, to provide a smooth transition from the splash screen to your app.
Chrome will choose the icon that closely matches the device resolution for the device. Providing 192px and 512px icons is sufficient for most cases, but you can provide additional icons for pixel perfection.
There are several additional properties that can be added to the web app manifest. Refer to the MDN Web App Manifest documentation for more information. You can learn more about display_override
in the explainer.