Cross-platform instrumentation vs. separate platform instrumentation

Amplitude customers often ask if they should use the same API key for the iOS and Android versions of the same app, or if they should tie web and mobile data together. The answer depends on the kind of apps you have and the kind of analyses you want to do.

Sometimes an app behaves differently on each individual platform (Android, iOS, and web), so your top priority should be to analyze how each one performs on its own. Other times, understanding a user's behavior across platforms is the top priority. You know your users can come from any platform, and you're more interested in a user's actions than the platform they were on when they took those actions.

When to do a cross-platform instrumentation

Cross-platform instrumentation makes sense in these situations:

• You expect frequent user crossover between platforms.
• You want to analyze user behavior across platforms as a key focus for your company. (This requires you to collect user IDs.)
• You have experience using the same API key in another analytics product.
• You've read and understood the advantages of using the same API keys.

This approach has two primary advantages: you can view totals across all platforms in a single unified view, and you can create funnels or retention charts that analyze user behavior across platforms.

When to do a separate platform instrumentation

Sometimes separate platform instrumentation makes more sense. For example:

• Your app acts as a standalone on each platform, and user crossover analysis isn't important.
• Your goal is to understand how users engage within each platform.

Consider these advantages:

• Platform differences: Even if your app has the same primary functions on iOS and Android, slight differences exist in how Amplitude tracks certain actions (for example, asking for permissions). These differences may warrant separation. Any slight differences in the apps themselves (such as showing different landing or tutorial screens) may also be easier to manage when separated.
• Different update cycles: Instrumentation changes happen all the time, and app updates rarely go live on the same day. Data and possibly new events from a new version on a certain platform could mix with data and old events from the old version, which pollutes the dashboard and takes focus away from the important metrics.
• Difficulty finding errors: Having events from multiple platforms on the same dashboard makes it more difficult to spot errors and bugs in instrumentation and make the necessary fixes.
• Web and mobile are very different: The experiences on web and mobile differ, and the kinds of events you want to track may also be very different.