Why is my calculated segment size much smaller than the estimated size shown in the preview?

This discrepancy typically occurs because the audience calculated for a push campaign only includes devices that are currently subscribed and have a valid push token. The segment preview, on the other hand, estimates the number of users or devices that match your filter criteria regardless of their subscription status.

For example, you may have many users who match your Tag criteria but never opted in to push notifications, or whose token was invalidated (app uninstalled, notification permission revoked). Those devices are excluded from the final calculated count, making it look smaller than the estimate.

What to check

• Compare the two numbers with subscription status in mind — a large gap usually just reflects the share of your matching audience that has no valid push token.
• If you need the raw number of everyone matching your filters regardless of token, export the segment via the API: call /exportSegment with "includeWithoutTokens": true, then read devicesCount from /exportSegment/result.
• If your goal is to reach the other devices of a user who matched the filter, tick "Include these users' other devices" when editing the segment. Note what this option actually does: it expands a match from the single matched device to every device registered under the same UserID. It does not add devices that have no push token.

Please Note: no segment option makes an unsubscribed device reachable. Devices without a valid push token still cannot receive push notifications; reach them over another channel (email, SMS, in-app) instead.