A quick reference guide to setting up your website for app indexing and deep linking
Having content inside your app indexed by a search engine, like content on your website, gives your app content visibility in Google, Apple Spotlight and Bing mobile search results. When content on your website is also available in your app, and a searcher already has your app installed, it’s possible to have your app open from those mobile search results instead of your website. This is the basic idea behind app indexing and deep linking.
App indexing = associating content inside your app with content on your website
Deep linking = connecting the associated content to your app
The screenshots below show a couple of example scenarios. Choosing the Etsy URL in the example on the left launches the Etsy app instead of the Etsy website. Choosing the NBC URL in the example on the right launches the NBC app instead of the NBC website. If the Etsy or NBC app weren’t already installed, the Etsy or NBC website would have opened instead of the app. In order to make this happen, content shared between the app and the website need to be associated.
Image: Example of Google search results opening the Etsy app from Android on the left and opening the NBC app from iOS on the right.
Associating the shared content and deep linking to it requires implementing properties on your website. It also involves enabling properties inside your app, which this article doesn’t go into. Depending on the operating system involved, not all the website properties are necessary. Some formats are interchangeable. Android rel=”alternate” as a meta tag or part of an XML sitemap both do the same thing. The Apple Smart App Banners app-argument and Facebook App Links both also do the same thing in iOS. An app-site-association file is necessary for iOS but not for Android. It can get confusing and it’s easy to forget what goes where in which format for each operating system.
Reducing confusion about which properties go where was the inspiration for creating cheat sheets. They are not intended to help you determine which properties to use for your particular situation. They are not intended to be comprehensive. They also don’t cover what you need to implement inside your app. They are a quick reference guide for properties used by each operating system. If you need more details, there are links to documentation included below.
Quick Reference Cheat Sheet
Benefits of App Indexing
- Ability to send organic search traffic into your app or to your website depending on which user experience you feel is best for mobile users
- For Android searchers, Google will show an app install button next to your homepage URL to people who don’t already have your app installed
- Increase engagement with people who already have your app installed
- Reintroduce your app through search results to people who may have forgotten they have it installed
- Acquire new app users
Mistakes to Avoid
- Bing uses Facebook App Links to understand content inside your app. If you choose not to implement App Links, you’re leaving Bing in the dark.
- Failing to implement the required minimum components for Facebook App Links and the Twitter App Card
- Implementing properties that aren’t required for iOS or for Android
- Mismatching website and app content
Statistics from Google Case Studies
After implementing app indexing and deep linking:
- Cookpad increased dormant app user re-engagement by 15% and weekly sessions per active user by 10%
- Etsy experienced an 11.6% increase in average daily app traffic from referral links
- Daily Mail / MailOnline experienced a 22.2% boost in search impressions for app users
- Daily Mail / MailOnline also found that visitors who wound up using their app via search spend 20% more time per visit, are two times more likely to share an article, and 28% more likely to view a video compared to general users
- Tabelog experienced an almost 10% increase in restaurant page views in their app immediately after indexing
Formatting Cheat Sheet
Facebook App Links
An open standard supported by iOS, Android, Google and Bing. These tags allow shared content to open inside your app. Apple supports them as an alternative to the Smart App Banners app-argument.
Twitter App Card
Similar to Facebook App Links but more specific to Twitter. Apple also supports them as an alternative to the Smart App Banners app-argument.
Both the rel=”alternate” meta tag and the rel=”alternate” XML sitemap tag tells Google which of your web pages have corresponding shared content in your app. They are interchangeable.
A JSON file that correlates app content to shared website content. It’s similar to a sitemap and is unique to iOS.
Apple Smart App Banners
The app-argument part of Smart App Banners is the iOS counterpart to the rel=”alternate” meta tag for Android. Apple supports both Facebook App Links and the Twitter App Card as alternatives to the Smart App Banners app-argument.