Tracking Users in Countly

Understanding Device ID

Countly uses a unique identifier called the device ID to decide which events, sessions, and user properties belong to the same user profile.

Your device ID strategy determines what a "user" means in Countly. The right choice depends on two things: whether you need the same person recognized across devices, and whether pre-authentication activity needs to be tracked.

Quick Decision Guide

Tracking Strategies

Each strategy changes both identity accuracy and when data becomes visible in Countly.

Strategy 1: Device-Based Tracking (Default)

Use this when the device itself is a good enough identity and cross-device tracking is not important.

Result: 1 device = 1 user in Countly

Choose this if: your product is usually one person per device, login is optional or absent, and you want the simplest implementation.

Do not choose this if: shared devices are common, the same customer uses multiple devices, or you need one durable user profile across platforms.

Strategy 2: Known User Tracking (after Auth tracking)

Use this when Countly should only start tracking after the user is authenticated or otherwise identified.

Result: 1 customer = 1 user across all devices

Choose this if: meaningful activity starts after login, pre-auth activity is not important, and consistent customer-level profiles matter.

Do not choose this if: users spend meaningful time as guests before login or you need to analyze anonymous behavior.

Strategy 3: Known User Tracking (pre and after Auth tracking)

Use this when pre-authentication activity matters, but you still want one clean known-user profile instead of separate anonymous users.

Result: 1 customer = 1 user with pre-authentication activity attached after identification

Choose this if: you need pre-auth activity tied to the final known user, and it is acceptable for that data to appear only after the user authenticates.

Do not choose this if: data must be visible immediately, many users may never finish authentication, or you want the simplest implementation.

Strategy 4: Anonymous and Known User Tracking

Use this when guest activity must be visible immediately and you also need to identify the user later.

Result: 1 customer can appear as one or more user profiles depending on how and when identification happens

Choose this if: pre-auth usage is a major part of the journey, such as browsing, trial usage, or anonymous checkout steps, and you need that data in Countly right away.

Do not choose this if: exact user counts are critical, you want the cleanest identity model, or frequent merges would create operational overhead.

Final Checks Before Production

• Is cross-device identity required? If yes, eliminate Strategy 1.
• Is anonymous or pre-auth activity important enough to report? If no, choose Strategy 2.
• Can pre-auth data wait until the user identifies themselves? If yes, Strategy 3 is usually the cleanest option.
• Do you need guest activity visible immediately even if user counts become less stable? If yes, Strategy 4 is the right fit.
• Will your team be comfortable with the added identity logic? If not, prefer the simpler strategy that still meets your reporting needs.

After you choose a strategy, share this implementation guide with your developers: