Sync to third-party destinations

Amplitude supports three types of syncs for cohorts, properties, computations, and predictions: on-demand syncs, automated syncs, and real-time syncs.

On-demand syncs are useful for audience testing and one-off campaigns. Automated syncs run on a daily or hourly schedule. As cohort audience membership or user predicted probabilities change, Amplitude Activation automatically adjusts cohort membership in connected destinations. Real-time syncs update each minute and work best for interactive use cases that require rapid updates.

You don't need CSV downloads or manual syncs. When users take an action in your app, Amplitude automatically syncs them to the relevant ad, email, or testing platform.

Feature availability

• Users on Starter, Plus, Growth, and Enterprise plans can use on-demand syncs.
• Users on Growth, Enterprise, and Plus plans can use automated syncs.
• Users on Growth and Enterprise plans can use real-time syncs.

Real-time syncs

With real-time syncs, Amplitude Activation sends updates to a partner destination almost as soon as a user enters or exits a cohort. This unlocks additional uses for cohort sync, such as timely and contextual messaging to end users. When you create a real-time sync, Amplitude Activation first sends the initial population to the destination. This can take several hours if the sync is large. After this initial sync, Amplitude sends updates every minute as users enter and exit the cohort.

Most destinations and cohorts support real-time cohort syncs. When partners fail or reject API requests, or when network delays and errors occur, Amplitude Analytics sends any changes as soon as the issue is resolved.

Real-time sync doesn't support select destinations that aren't designed for frequent updates, such as ad destinations and S3, or destinations with strict integration limits that prevent frequent syncing.

Real-time sync doesn't support some complex or very large cohorts because of high computation cost. Real-time sync can send cohort membership to destinations, but not computations, properties, or predictions.

Create a new sync

To create a new sync, follow these steps:

1. Click + New and click the Sync tile. The Create New Sync modal appears.

2. Select the sync type to create: cohort, recommendation, user property, or computation sync. Then click Next.

3. From the drop-down list, select the specific item you want to sync. Then click Next.

4. Choose the destination to sync to. If the destination doesn't appear, click + Add or Manage Destinations and configure the destination there. Then click Next.

5. Choose whether to create an on-demand sync, recurring sync, or real-time sync. Recurring syncs run on an hourly or daily schedule, while real-time syncs update each minute.

   Depending on your choice in step 4, you may also need to specify a customer account or API target to sync to.

6. Click Sync. Your sync is active.

Email notifications

Amplitude automatically sends email alerts for cohort sync jobs:

• Success notifications: Receive confirmation when your cohort sync completes successfully.
• Failure notifications: Receive an alert when a sync job fails, so you can address issues quickly.

These notifications help you monitor cohort sync status without manually checking the platform.

View sync details

After you create a sync, click the sync name in the Syncs panel to view its details.

The Details tab provides basic information about the sync. The example above is a cohort sync, so the Details tab provides a definition of the cohort, as well as a chart detailing its population over time. The Syncs tab shows each destination that receives this sync.

On the Comparisons tab, you can view a head-to-head comparison between this synced cohort and another cohort of your choosing. You can break down the results of the User Composition chart by user property using the Composition by drop-down.

To view a list of your synced cohorts from within Amplitude Analytics, click Cohorts and open the Synced Cohorts tab.

Understanding cohort sync discrepancies

When syncing cohorts from Amplitude to a third-party destination, you may notice differences between the user numbers in Amplitude and on the partner's platform. Understanding why these differences occur and how to check which users transferred successfully can help you fix these issues.

Amplitude lets you choose any user properties to sync. This aids in customization, but it also requires careful planning to minimize discrepancies during a cohort sync.

Common reasons for differences in cohort syncs include:

• Unresolved mapping: If a user property isn't set, or is NULL, Amplitude can't sync the user attached to the property. For example, if you're syncing a cohort of 100 users to a platform using email as the User_ID, but only 50 users provided an email, only those 50 users sync. Check and fix your data at the source, update it in Amplitude, and then run another sync.
• Invalid mapped properties: Properties that don't conform to the expected format in third-party destinations can cause partial or failed syncs. For example, the downstream destination may not accept a particular identifier format, such as email or phone number.

Warning when updating cohort mapping

Amplitude issues a warning if you attempt to modify the Amplitude user property mapping, because modifying the mapping can affect active cohort syncs. Click View Syncs to view the sync that could be affected. From there, decide if you want to turn off the sync.

Even if you don't receive a warning, be careful when modifying mapping properties. Mapping changes can cause unexpected changes in the number of users tracked.

For example, if you stop mapping by email addresses and switch to phone numbers, users previously synced with their emails don't receive updates. Your change only affects new users. Amplitude syncs new users based on phone numbers, while previously existing users still sync based on email addresses. Over time, this can lead to data discrepancies.

If your cohort sync process has been in place for some time and you're considering changing the mapping, create a new sync destination first. Then proceed with the sync using this new target.

View sync history

The cohort sync history page provides a detailed breakdown of cohort syncs over the last 14 days. Each cohort sync provides a list of skipped, added, or removed users. To access the page, follow these steps:

1. Click the Cohorts tab.
2. Choose the specific cohort of interest.
3. Click the Syncs tab.
4. If the cohort sync includes multiple destinations, select the appropriate cohort destination.
5. Click the History tab.

Inspect exported cohorts using CSV export

To find out which users and how many users Amplitude exported from your cohort to your third-party destination, export a CSV containing all exported users.

The CSV export includes the following columns:

• Amplitude_id: Displays the unique Amplitude ID associated with each user.
• Operation: Indicates whether Amplitude added or removed a user from cohort membership.
• Mapped properties: This column shows the mapped user identifier for the cohort sync.
• Skip_detected: Shows if Amplitude skipped a user during the cohort sync process.
• Skip_reason: High-level categorization of why Amplitude skipped a user.
  • Unresolved mapping: Amplitude skipped this user during the cohort sync because the mapped property used to identify the user is missing or has no value.
  • Rejected by partner: The third-party destination rejected this user because the mapped property doesn't adhere to the required format. For example, if data fields aren't in the correct numeric or email format, the destination excludes the user from the cohort sync.

Some user properties may be incomplete or out of compliance with the target platform's criteria. A cohort sync success rate over 80% is often acceptable for advertising campaigns. For email campaigns or A/B testing, use a rate above 95%.

If there are many skipped entries, there may be a data quality issue at the source. To resolve this issue, review the CSV file to pinpoint discrepancies. Then make appropriate corrections to the user data when you're importing it into Amplitude. After you make corrections, launch the cohort sync process again to confirm the accuracy and consistency of your data.

Additional considerations

• Real-time cohort sync: With Amplitude's Real-Time Sync (RTS) feature, the cohort sync history page doesn't allow you to export a CSV for users skipped during the sync. For detailed tracking of skipped users, use hourly or daily syncs instead of real-time syncs.
• Users are silently dropped upon reaching destination: Some destinations may return a 2XX response to indicate a successful cohort sync from Amplitude, even though the destination silently dropped users who didn't meet its criteria. In these cases, confirm that Amplitude exported a specific user by checking the CSV file.

Supported destinations

Refer to the Destination Catalog.