Smart App Banner: How to Add It, Test It and Measure It

A Smart App Banner is the strip Safari on iOS shows at the top of your website, offering your app with a View or Open button. You add it with one meta tag, <meta name="apple-itunes-app" content="app-id=YOUR_APP_ID">, in the <head> of each page where it should appear.

What the banner does

Visitor doesn't have the app: tapping the banner takes them to your App Store page. When they come back to your site, the banner shows a progress bar while the app downloads, then its View button changes to Open.
Visitor has the app: tapping the banner opens it.
Visitor closes it: the banner doesn't come back when they return to the page.
Your app doesn't run on their device, or isn't sold where they are: the banner doesn't appear at all. Safari works this out for you.

Because it looks the same on every site, people know a tap goes to the App Store and not to an ad. It sits at the top of the page instead of covering it.

Add it in three steps

Find your app ID. In App Store Connect, select your app, then General › App Information. Your app ID is the number shown as Apple ID. You can also find it in App Store Marketing Tools: it's the number between id and ? in your app's link.
Add the tag to the <head> of every page that should show the banner. If your site has a shared layout or template, put it there once.

<meta name="apple-itunes-app" content="app-id=123456789">

Test on a real device, in Safari. The banner doesn't appear in the iOS Simulator, and it can't be shown inside a frame.

Send people to the right screen with app-argument

The tag takes a second, optional parameter, app-argument: a URL handed to your app when someone who already has it taps the banner. Use it so a visitor lands on the same thing in the app that they were reading on the web, not on the app's home screen.

<meta name="apple-itunes-app" content="app-id=123456789, app-argument=https://example.com/recipes/42">

Apple's examples of what to pass:

The visitor is…	Pass	So the app can…
Deep in your site	The page's full URL	Open the matching screen
Searching your site	The search query	Continue the search without retyping
Halfway through creating something	A session ID	Pick up their work where they left off

You can build app-argument for each page on the server. Any format works as long as it's a valid URL. In the app, read it where your app delegate receives an incoming URL, and route from there.

Measure what the banner brings

A banner you can't measure is easy to forget about. App Store Connect can count the downloads it brings, the same way it counts any campaign link:

In App Store Connect, open your app's Analytics tab, then Acquisition › Campaigns, and add a campaign. Its name is your campaign token (ct). Creating one also gives you your provider token (pt), which identifies your developer account and stays the same for every campaign.
Add your campaign token and provider token to your Smart App Banner, following the instructions on Apple's campaign links page (linked under Sources). You can't make up a provider token: you get it only by creating a campaign link first.
Read the results under Analytics › Metrics, filtered by your campaign.

Three things to know before you look:

Campaigns become available only once your app has analytics data. If your app is new, the add (+) button may not appear yet; Apple suggests checking again once it has been live and getting downloads for at least 24 hours.
A campaign shows up at least 24 hours after it starts, and each number appears only once it reaches 5 in the dates you picked. Widen the dates if a number is missing.
A first-time download counts for the campaign when it happens within 24 hours of the visitor using it. If someone clicks more than one campaign link within a given timeframe, only the most recent one gets credit for later sales.

Give the banner its own campaign token, separate from the links in your emails or posts, so you can tell them apart.

Why the banner doesn't show

The visitor isn't in Safari. Banners show only in Safari, not in other browsers or in the browsers built into apps.
You're testing in the Simulator. Use a real device.
The page is in a frame. Banners can't appear inside one.
You closed it earlier. Once dismissed, it doesn't come back on that page.
Your app doesn't support the device, or isn't available in that country or region. Safari hides the banner on purpose.
The tag isn't in the page's <head>. View the page source on the live site. While you're there, check that the app-id matches the Apple ID in App Store Connect.

Questions

Does it work on Android? No. Smart App Banners show only in Safari, and Google has never released an Android equivalent of the apple-itunes-app tag.

Do I need it on every page? Only on the pages where it should appear. If your site has a shared layout, adding it there puts it on every page, with app-argument set per page.

Smart App Banner: how to add it, test it and measure it