The goal is to allow web apps to appear in the UI for picking an app to share

to.

In combination with the [Web Share API](https://github.com/mgiuca/web-share)

In combination with the [Web Share API](https://github.com/WICG/web-share)

(being proposed in parallel), this would allow cross-sharing between websites on

any platform (even those without a native sharing system).

### Sharing from web to web on mobile

Here we see the interaction between the [Web Share

API](https://github.com/mgiuca/web-share) and the Share Target API. You could

API](https://github.com/WICG/web-share) and the Share Target API. You could

also share from a native app (depending on the system).


For more technical details on integrating with native apps, see [Native

Integration Story](native.md).

Users may wish to share photos and other files, not just links. We aim

to support this in the future, with web share targets able to specify

in their manifests which MIME types they accept.

## Sample code

Here's how to register a website to appear in the list of apps that can handle a

### Why not use registerProtocolHandler?

This is discussed at length in the [Web Share

Explainer](https://github.com/mgiuca/web-share/blob/master/docs/explainer.md),

and depends on the outcome of that decision. If we use a URI scheme for Share

(instead of an API), then it would make sense to use the existing

Explainer](https://github.com/WICG/web-share/blob/master/docs/explainer.md#user-content-why-not-make-a-share-uri-scheme-like-mailto-instead-of-a-javascript-api).

If we used a URI scheme for Share (instead of an API), then it would make sense

to use the existing

[registerProtocolHandler](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/registerProtocolHandler)

API to let websites receive shares.

However, there are a number of downsides to this approach, discussed in the

other document. This is an open question.

other document.

share systems, for exploring how a user agent might automatically map the [Share

Target API](explainer.md) into the native system. See also: [Share API Native

Integration

Survey](https://github.com/mgiuca/web-share/blob/master/docs/native.md).

Survey](https://github.com/WICG/web-share/blob/master/docs/native.md).

*Note:* I (mgiuca@chromium.org) am not very familiar with these details. I

gathered this information from reading the online documentation and

## Summary

Unlike the web-to-native sharing (in the [Share

API](https://github.com/mgiuca/web-share), which is generally pretty

API](https://github.com/WICG/web-share), which is generally pretty

straightforward to route into a system share, native-to-web is usually hard or

impossible for one reason: operating systems don't like letting one application

dynamically register multiple handlers for things (with the notable exception of

1. Declare the browser itself as a system share target, then have users pick the

browser, and display a sub-picker within the browser for web apps, or

2. Only support web-to-web sharing (showing a picker within the browser when a

website uses the [Share API](https://github.com/mgiuca/web-share)).

website uses the [Share API](https://github.com/WICG/web-share)).