> ## Documentation Index > Fetch the complete documentation index at: https://docs.permutive.com/llms.txt > Use this file to discover all available pages before exploring further. # Cohorts and Activations > Understanding user segmentation in the Permutive JavaScript SDK export const CohortsVsActivationsTable = () =>
Aspect Cohorts Activations
Definition All segments a user belongs to Cohorts configured for specific platforms
Scope Entire Permutive system Platform-specific
Purpose User segmentation Ad targeting
Configuration Automatic based on events Configured in dashboard
; export const ActivationTypesTable = () =>
Activation Type Platform Use Case
dfp Google Ad Manager Standard behavioral cohort activations
dfp_contextual Google Ad Manager Real-time contextual cohorts
appnexus_adserver Xandr/AppNexus Standard behavioral cohort activations
appnexus_adserver_contextual Xandr/AppNexus Real-time contextual cohorts
freewheel Freewheel CTV/video ad targeting
; export const ActivationDefinition = () => <>

Activations are subsets of cohorts configured for specific ad platforms. Not all cohorts are activated for all platforms—activations allow you to control which cohorts are sent to which ad networks.

; export const CohortTypes = () =>

Based on user actions and event patterns tracked through the SDK.

Example: A user who reads 5+ sports articles becomes part of the "sports_enthusiast" cohort.

{`User reads article about tennis
    ↓
Track event: "Pageview" with properties
    ↓
Permutive evaluates: "User read 3+ sports articles in 7 days?"
    ↓
User enters cohort: "sports_enthusiast"`}

Generated using machine learning models that predict user characteristics.

Example: ML model predicts user is likely to purchase premium subscription based on browsing patterns.

Based on real-time content analysis of the current page or video being viewed.

Example: User viewing a page about electric vehicles gets contextual cohort "automotive_electric_vehicles" for that session.

Key characteristics:

 ; export const CohortDefinition = () => <>

A cohort is a privacy-safe representation of an audience.

Traditionally, user IDs like third-party cookies have been used to communicate information about audiences and activate (target) them. A publisher might communicate behavioral data for a user to an ad server by attaching the data to a cookie ID. The ad server uses the cookie ID to record information about the user—both information from the publisher and other data parties they work with—and the ad server can later target an ad for a request from that user based on the information it has attached to their cookie ID.

With cohorts, a code represents the group of users that fall into an audience. In the example above, when the publisher requests an ad from the ad server for the user, it includes the cohort code in the request, but not a user ID. The ad server can use the cohort code(s) to decision on the ad to respond with, but no other publisher or user data is leaked and a profile of the user cannot be built.

By removing user identifiers from the equation, users' privacy is protected, the publisher's data cannot be targeted off of their site/app, and publishers can provide reachability (scale) to the ecosystem since cohorts can be built & activated in environments like Apple Safari, Mozilla Firefox, and iOS where third-party cookies and other deterministic identifiers are prohibited.

; Cohorts are the core mechanism for user segmentation in Permutive. The SDK provides methods to check cohort membership and react to changes in real-time. ## What are Cohorts ## Cohort Types ## How Cohorts Work 1. **Events are tracked** via the SDK (pageviews, custom events, etc.) 2. **Rules are evaluated** against user behavior 3. **Users enter/exit cohorts** based on rule matching 4. **Cohorts are stored locally** in the browser 5. **Cohorts are passed to ad platforms** for targeting ``` User views sports article → Track Pageview event ↓ Permutive evaluates rules ↓ User enters "sports_enthusiast" cohort ↓ Cohort stored in localStorage ↓ Cohort passed to ad requests ``` ## Activations ### Activation Types ## Cohorts vs Activations ## Accessing Cohorts ### Get All Segments ```javascript theme={"dark"} // Get all cohorts the user belongs to permutive.segments(function(segments) { console.log('All segments:', segments); // Output: [12345, 67890, 11111, ...] }); ``` ### Get Platform-Specific Segments ```javascript theme={"dark"} // Get cohorts activated for Google Ad Manager (DFP) permutive.segments(function(segments) { console.log('DFP segments:', segments); }, 'dfp'); // Get cohorts activated for AppNexus permutive.segments(function(segments) { console.log('AppNexus segments:', segments); }, 'appnexus'); ``` ### Check Single Cohort Membership ```javascript theme={"dark"} // Check if user is in a specific cohort permutive.segment(12345, function(inCohort) { if (inCohort) { console.log('User is in cohort 12345'); showPremiumContent(); } else { console.log('User is NOT in cohort 12345'); showStandardContent(); } }); ``` ### Wait for Cohort Data Use `ready()` with the `'realtime'` stage to ensure cohort data is available: ```javascript theme={"dark"} permutive.ready(function() { // Cohort data is now available permutive.segments(function(segments) { console.log('Segments (after ready):', segments); }); }, 'realtime'); ``` ## Real-Time Triggers React to cohort changes as they happen: ```javascript theme={"dark"} // Trigger when user enters/exits a cohort permutive.trigger(12345, 'result', function(obj) { if (obj.result) { console.log('User just ENTERED cohort 12345'); } else { console.log('User just EXITED cohort 12345'); } }); ``` See [Real-Time Triggers](/sdks/web/javascript-sdk/features/real-time-triggers) for more details. ## localStorage Structure Cohorts are stored in localStorage for fast access and ad targeting: | Key | Purpose | | ------------- | ----------------------------------- | | `_psegs` | All cohorts | | `_pdfps` | Google Ad Manager (DFP) activations | | `_papns` | AppNexus activations | | `_prubicons` | Rubicon activations | | `_ppubmatics` | PubMatic activations | ```javascript theme={"dark"} // Direct localStorage access (for debugging) var allCohorts = JSON.parse(localStorage.getItem('_psegs') || '[]'); var dfpCohorts = JSON.parse(localStorage.getItem('_pdfps') || '[]'); ``` Always use the SDK methods (`segments()`, `segment()`) rather than reading localStorage directly in production code. The SDK handles synchronization and edge cases. ## Using Cohorts with Ad Platforms ### Google Ad Manager ```javascript theme={"dark"} // Using the DFP addon (automatic) permutive.addon('web', { page: { type: 'article' } }); // Targeting is set automatically // Manual targeting permutive.segments(function(segments) { googletag.cmd.push(function() { googletag.pubads().setTargeting('permutive', segments); }); }, 'dfp'); ``` ### Prebid.js Cohorts are automatically passed to Prebid via the RTD module. See [Prebid Integration](/sdks/web/javascript-sdk/integrations/prebid). ### AppNexus/Xandr ```javascript theme={"dark"} permutive.segments(function(segments) { // Use segments for AppNexus targeting apntag.setKeywords('permutive', segments); }, 'appnexus'); ``` ## Cohort Patterns ```javascript theme={"dark"} // Personalize content based on cohorts permutive.ready(function() { permutive.segment(12345, function(isPremiumUser) { if (isPremiumUser) { showPremiumLayout(); hideAds(); } }); }, 'realtime'); ``` ```javascript theme={"dark"} // Adjust paywall based on user segments permutive.segments(function(segments) { var isHighValueUser = segments.includes(54321); var isFrequentReader = segments.includes(98765); if (isHighValueUser && !isFrequentReader) { showSoftPaywall(); } }); ``` ```javascript theme={"dark"} // Use cohorts for A/B test targeting permutive.segment(11111, function(inTestGroup) { if (inTestGroup) { runExperimentVariantB(); } else { runExperimentVariantA(); } }); ``` ```javascript theme={"dark"} // Pass cohorts to analytics permutive.segments(function(segments) { analytics.identify({ permutive_cohorts: segments.slice(0, 10) // Top 10 cohorts }); }); ``` ## Event-Based Cohort Updates Cohorts update in real-time as users take actions: ```javascript theme={"dark"} // User reads an article about sports permutive.addon('web', { page: { type: 'article', article: { categories: ['sports', 'football'] } } }); // Moments later, check if they entered the sports cohort permutive.trigger(12345, 'segment', function(inSportsCohort) { if (inSportsCohort) { console.log('User just qualified for sports cohort!'); } }); ``` ## Debugging Cohorts Enable debug mode to see cohort activity: ``` ?__permutive.loggingEnabled=true ``` Console output includes: ``` [Permutive] Segments updated: [12345, 67890, ...] [Permutive] User entered segment: 12345 [Permutive] DFP segments: [12345] ``` ## Troubleshooting **Problem:** No cohorts even after tracking events. **Solutions:** * Use `ready('realtime')` to wait for data * Check that events are being tracked (debug mode) * Verify cohorts are configured in dashboard * Ensure user hasn't opted out (consent) * Allow time for cohort processing (seconds to minutes) **Problem:** Events tracked but user not in cohort. **Solutions:** * Verify cohort rules in dashboard * Check event properties match rule conditions * Confirm cohort is active (not paused/archived) * Check cohort minimum threshold/frequency **Problem:** User in cohort but activation array differs. **Solutions:** * Check that cohort is activated for the platform * Verify activation configuration in dashboard * Use correct type parameter: `segments(cb, 'dfp')` **Problem:** Cohorts not updating after new events. **Solutions:** * Cohorts update in real-time but may take a few seconds * Refresh page to trigger re-evaluation * Check that new events are actually being tracked * Use `trigger()` for real-time change detection ## Related Documentation React to cohort changes Build cohorts in dashboard Content-based cohorts GAM targeting setup