LinkedIn li_fat_id Explained: Complete Technical Guide

LinkedIn's li_fat_id is the most powerful—yet underutilized—B2B tracking parameter available to marketers.

While most platforms (Google, Facebook, Pinterest) use generic click IDs, LinkedIn's li_fat_id encodes rich B2B targeting data including job titles, company size, seniority levels, and industry targeting. This makes it uniquely valuable for B2B marketers running account-based marketing (ABM) campaigns.

Yet many marketers ignore li_fat_id in favor of manual UTM parameters, losing access to this valuable targeting intelligence.

Here's everything you need to know about li_fat_id, how it works, and why you should use it instead of manual UTMs for LinkedIn Ads.

What is li_fat_id?

li_fat_id = LinkedIn First-Party Ad Tracking ID

It's an automatically-generated parameter that LinkedIn appends to every LinkedIn Ads click, similar to how Google uses gclid and Facebook uses fbclid.

Example URL with li_fat_id

Before click (LinkedIn Ads):

https://yourcompany.com/demo

After click (what user sees):

https://yourcompany.com/demo?li_fat_id=abc123xyz456def789ghi

LinkedIn automatically injects the li_fat_id parameter when someone clicks your ad. No manual configuration required.

What Data Does li_fat_id Encode?

Unlike generic platform click IDs, li_fat_id encodes rich B2B targeting metadata:

Campaign Identifiers

• Campaign ID: Unique identifier for the campaign
• Creative ID: Which specific ad variation was clicked
• Ad Format: Sponsored Content, Message Ad, Text Ad, etc.
• Placement: Feed, Messaging, Right Rail

B2B Targeting Data (LinkedIn's Unique Advantage)

• Job Title: The user's current job title
• Seniority Level: Executive, Director, Manager, Entry-Level, etc.
• Company Size: Employee count brackets
• Industry: LinkedIn's industry taxonomy
• Job Function: Marketing, Sales, Engineering, etc.
• Company Name: (For ABM campaigns with company targeting)

Technical Metadata

• Device Type: Desktop, Mobile, Tablet
• Operating System: Windows, Mac, iOS, Android
• Click Timestamp: Precise time of ad click
• Member ID (hashed): LinkedIn member identifier (privacy-compliant)

This is data you CANNOT capture with manual UTM parameters.

How li_fat_id Works: Technical Flow

1. LinkedIn Ads Setup

You create a campaign in LinkedIn Campaign Manager targeting specific B2B audiences:

Campaign: SaaS Product Launch
Target Audience:
- Job Titles: VP Marketing, Marketing Director, CMO
- Company Size: 200-1,000 employees
- Industries: Software, Technology
- Seniority: VP-level, CXO

2. Ad Click Event

When a LinkedIn member matching your criteria clicks your ad:

1. LinkedIn generates li_fat_id: A unique, encrypted string containing all targeting metadata
2. Appends to destination URL: LinkedIn adds ?li_fat_id=[value] to your landing page URL
3. User lands on your site: With li_fat_id in the URL
4. GA4/analytics captures: The full URL including li_fat_id

3. Attribution in GA4

GA4 automatically recognizes li_fat_id and attributes traffic correctly:

• Source: linkedin
• Medium: cpc (or paidsocial, depending on GA4 version)
• Campaign: Extracted from li_fat_id metadata
• Default Channel: Paid Social

4. LinkedIn Campaign Manager Integration

The li_fat_id connects the click back to LinkedIn:

• Conversion tracking: LinkedIn sees which li_fat_id values led to conversions
• Attribution reporting: Detailed performance by job title, seniority, company size
• Optimization: LinkedIn's algorithm optimizes delivery based on which segments convert

This creates a closed-loop attribution system between your website and LinkedIn Ads.

li_fat_id vs. Manual UTMs: Detailed Comparison

Verdict: li_fat_id wins in every technical and business category for LinkedIn Ads.

Why Use li_fat_id Instead of Manual UTMs

1. Automatic B2B Intelligence

With li_fat_id, LinkedIn Campaign Manager shows:

• Which job titles convert best (e.g., "VP Marketing" = 8% conversion rate, "Marketing Manager" = 3%)
• Which company sizes have highest ROI (200-500 employees = $150 CAC, 1,000+ = $300 CAC)
• Which seniority levels engage most (Director-level = 4min avg. session, Manager-level = 2min)

With manual UTMs, you see:

• Traffic came from LinkedIn
• Campaign name (that you manually set)
• No job title, seniority, or company data

The difference: li_fat_id gives you actionable B2B insights that manual UTMs cannot provide.

2. Zero Configuration, Zero Errors

Manual UTMs require:

https://yoursite.com/demo?utm_source=linkedin&utm_medium=cpc&utm_campaign=product-launch-q4-2025&utm_content=variant-a

Issues:

• Team member typos: utm_source=linkdin (misspelled)
• Inconsistent case: LinkedIn vs linkedin (creates duplicate sources in GA4)
• Missing parameters: Forgot utm_campaign
• Wrong medium: Used paid-social instead of cpc

li_fat_id requires:

https://yoursite.com/demo

LinkedIn handles everything automatically. Zero errors, zero maintenance.

3. Enhanced Conversion Tracking

LinkedIn's Conversion API (CAPI) works seamlessly with li_fat_id to:

• Match conversions across devices: User clicks ad on mobile, converts on desktop → LinkedIn connects via member ID
• Attribute view-through conversions: User saw ad but didn't click → later converts → LinkedIn attributes
• Reduce attribution loss from iOS 14+ tracking restrictions

Manual UTMs rely on cookie-based tracking, which breaks with:

• Safari ITP (Intelligent Tracking Prevention)
• Firefox ETP (Enhanced Tracking Protection)
• iOS 14+ App Tracking Transparency

Result: li_fat_id delivers 20-30% more accurate conversion attribution than manual UTMs for LinkedIn campaigns.

How to Enable li_fat_id (It's Already On)

Good news: li_fat_id is automatically enabled for all LinkedIn Ads accounts created after 2018.

How to verify:

Step 1: Check LinkedIn Campaign Manager

1. Log into LinkedIn Campaign Manager
2. Navigate to Account Settings → Tracking
3. Look for "Auto-tagging" or "Enable conversion tracking"
4. Should show: ✅ Enabled

If you see "Disabled", click Enable.

Step 2: Verify in GA4

1. Run a test click on one of your LinkedIn ads
2. Open GA4 → Reports → Realtime
3. Check the URL for the session
4. Should see: ?li_fat_id=[long string]

Step 3: Confirm LinkedIn Campaign Manager Integration

1. In LinkedIn Campaign Manager → Campaign → Performance
2. If li_fat_id is working, you'll see conversion data populate
3. Attributed to specific campaigns, ad creatives, and targeting segments

Integration with GA4

GA4 handles li_fat_id automatically through its default channel grouping logic.

How GA4 Processes li_fat_id

When GA4 sees a URL with li_fat_id:

https://yoursite.com/demo?li_fat_id=abc123xyz

GA4 extracts:

• Source: linkedin (identified from li_fat_id pattern)
• Medium: cpc (or paidsocial, depending on GA4 configuration)
• Campaign: Extracted from li_fat_id metadata (if LinkedIn sends campaign name)

Default Channel assignment: Paid Social

Viewing LinkedIn Traffic in GA4

Standard Report:

1. GA4 → Reports → Acquisition → Traffic acquisition
2. Filter: Session source = linkedin
3. You'll see:
   • Source / Medium: linkedin / cpc (or linkedin / paidsocial)
   • Sessions, conversions, revenue attributed correctly

Custom Report (Advanced): Create custom dimensions to extract li_fat_id metadata:

1. GA4 → Admin → Custom definitions → Create custom dimension
2. Dimension name: LinkedIn Fat ID
3. Event parameter: li_fat_id
4. Use in explorations to analyze performance by li_fat_id values

Recommended GA4 Setup for LinkedIn

Create segments for LinkedIn performance analysis:

Segment 1: LinkedIn Paid Traffic

• Source = linkedin
• Medium = cpc OR paidsocial

Segment 2: High-Intent LinkedIn Visitors (requires Insight Tag data)

• Source = linkedin
• Medium = cpc
• Session duration > 2 minutes OR pages per session > 3

Segment 3: LinkedIn ABM Accounts (requires CRM integration)

• Source = linkedin
• User matched to target account list

Advanced Use Cases

1. Account-Based Marketing (ABM) Attribution

If you're running LinkedIn's ABM campaigns (targeting specific companies by name):

li_fat_id captures:

• Which target accounts clicked ads
• Which companies converted
• ROI per target account

How to access:

1. LinkedIn Campaign Manager → Demographics tab
2. Filter by Company
3. See conversion rates by company name

Use case: Your $50,000 ABM campaign targeted 100 enterprise accounts. li_fat_id shows that 15 accounts clicked, 3 converted. You can identify the exact companies and focus sales outreach.

Manual UTMs: Cannot capture company-level data.

2. Job Title Performance Analysis

Question: Do "VPs" or "Directors" have higher conversion rates for our $10k/year product?

With li_fat_id:

1. LinkedIn Campaign Manager → Demographics → Job Seniority
2. See conversion rates:
   • VP-level: 12% conversion rate
   • Director-level: 6% conversion rate
3. Action: Increase bids for VP-level targeting, reduce Director budget

With manual UTMs: Cannot differentiate. All LinkedIn traffic is "linkedin / cpc".

3. Device + Job Title Cross-Analysis

Question: Do mobile users at Director-level convert differently than desktop users?

With li_fat_id (in LinkedIn Campaign Manager):

• Filter: Device = Mobile, Job Seniority = Director → 2% conversion rate
• Filter: Device = Desktop, Job Seniority = Director → 8% conversion rate
• Action: Exclude mobile for Director targeting, focus desktop

With manual UTMs: Can see device type in GA4, but not combined with job title.

Common Issues & Troubleshooting

Issue 1: li_fat_id + Manual UTMs = Duplicate Sessions

Scenario: You added manual UTMs to LinkedIn Ads URLs, but LinkedIn still appends li_fat_id.

Result: GA4 creates duplicate sessions (one for UTMs, one for li_fat_id).

Fix: Remove manual UTMs. Let li_fat_id handle attribution alone. See our guide: Fix LinkedIn UTM Conflict

Issue 2: li_fat_id Shows as "Referral" Instead of "Paid Social"

Scenario: LinkedIn traffic appears as "linkedin / referral" instead of "linkedin / cpc".

Cause: GA4 isn't recognizing li_fat_id as a paid parameter.

Fix:

1. Verify auto-tagging is enabled in LinkedIn Campaign Manager
2. Check GA4's channel grouping rules include li_fat_id
3. If needed, create custom channel group assigning li_fat_id to Paid Social

Issue 3: No Conversion Data in LinkedIn Campaign Manager

Scenario: GA4 shows conversions from LinkedIn traffic, but LinkedIn Campaign Manager shows zero conversions.

Cause: LinkedIn Insight Tag not installed or conversion tracking not configured.

Fix:

1. Install LinkedIn Insight Tag on your website
2. Set up conversion events in LinkedIn Campaign Manager
3. Match conversion events between GA4 and LinkedIn (e.g., "demo_request")

See: LinkedIn Conversion Tracking Setup Guide

FAQ

What does li_fat_id stand for?

LinkedIn First-Party Ad Tracking ID. It's LinkedIn's proprietary click tracking parameter, similar to Google's gclid or Facebook's fbclid.

Can I decode li_fat_id to see the targeting data?

Not directly. li_fat_id is an encrypted identifier. However, LinkedIn Campaign Manager decrypts it automatically and shows you the targeting data (job title, seniority, company, etc.) in campaign performance reports.

Does li_fat_id work for organic LinkedIn posts?

No. li_fat_id is only appended to LinkedIn Ads clicks. Organic LinkedIn traffic (posts shared by users, company page posts) appears as "linkedin / referral" in GA4 without li_fat_id.

Should I use both li_fat_id and manual UTMs?

No. Using both creates duplicate sessions in GA4 and fragments your conversion data. Choose one:

• Recommended: li_fat_id only (for automatic B2B tracking)
• Alternative: Manual UTMs only (if you must maintain UTM consistency across all channels, but you'll lose B2B targeting insights)

Most B2B marketers choose li_fat_id for its superior targeting intelligence.

Does li_fat_id expire or get truncated?

li_fat_id values don't expire, but they can be removed by:

• Redirects: If your landing page redirects to another domain, li_fat_id may be stripped
• Link shorteners: Services like Bitly may truncate long URLs including li_fat_id
• Email platforms: Some email clients strip query parameters from links

Prevention: Use direct landing pages without redirects, and test your full funnel.

Can I see which specific job titles converted in GA4?

Not directly in GA4. Job title data is visible only in LinkedIn Campaign Manager under Demographics → Job Title. GA4 shows aggregate LinkedIn traffic without job title granularity.

For deep B2B analysis, use LinkedIn Campaign Manager as your source of truth for targeting performance.

Does li_fat_id work with LinkedIn's Account-Based Marketing (ABM) campaigns?

Yes! li_fat_id is critical for ABM measurement. When you target specific companies using LinkedIn's ABM features, li_fat_id captures:

• Which target accounts clicked your ads
• Which companies converted
• ROI per target account

View this data in LinkedIn Campaign Manager → Demographics → Company.

How long is li_fat_id stored in GA4?

GA4 stores li_fat_id as part of the session data. Standard GA4 data retention:

• 2 months (default for free properties)
• 14 months (maximum for free properties)
• Up to 50 months (for GA360 properties)

For longer historical analysis, export data to BigQuery.

Can I use li_fat_id with Google Tag Manager?

Yes. li_fat_id passes through Google Tag Manager like any URL parameter:

1. GTM captures the full landing page URL including li_fat_id
2. GA4 tag fires with li_fat_id in the URL
3. GA4 processes li_fat_id automatically

No special GTM configuration needed.

What if my UTM naming convention requires manual UTMs for consistency?

If your organization mandates UTM consistency across all channels (Google Ads, Facebook, LinkedIn), you have two options:

1. Prioritize accuracy (recommended): Use li_fat_id for LinkedIn, accept that LinkedIn medium = "cpc" (not your custom naming)
2. Prioritize consistency: Use manual UTMs across all channels, accept:
   • Loss of B2B targeting insights (job title, seniority, company)
   • Duplicate sessions if li_fat_id still appends
   • Need for manual data cleanup

Most B2B organizations choose Option 1 and adapt their reporting to handle LinkedIn's li_fat_id separately.

Related Resources

Internal Guides

• Fix LinkedIn UTM Conflict - How to resolve duplicate sessions from li_fat_id + manual UTMs
• LinkedIn li_fat_id UTM Strategy - When to use li_fat_id vs. manual UTMs
• Platform Click ID Conflicts - Understanding auto-tagging across all platforms

LinkedIn Official Documentation

• LinkedIn Insight Tag Setup - Official guide to LinkedIn conversion tracking
• LinkedIn Campaign Manager Help - Official documentation for campaign tracking
• LinkedIn Conversion Tracking Best Practices

External Resources

• Google Analytics Default Channel Grouping - How GA4 assigns li_fat_id to channels

Conclusion

li_fat_id is the most powerful B2B tracking parameter available to marketers.

Unlike generic click IDs from other platforms, li_fat_id captures rich targeting data—job titles, seniority levels, company sizes, industries—that manual UTM parameters cannot provide.

For LinkedIn Ads, there's no legitimate reason to use manual UTMs:

• li_fat_id provides superior attribution
• Zero setup and zero errors
• Automatic B2B intelligence
• Seamless GA4 and Conversion API integration

Recommended setup:

1. Verify auto-tagging is enabled in LinkedIn Campaign Manager
2. Remove any manual UTM parameters from LinkedIn Ads URLs
3. Let li_fat_id handle all attribution
4. Use LinkedIn Campaign Manager for B2B targeting analysis
5. Use GA4 for aggregate conversion tracking

Result: Clean, accurate LinkedIn Ads attribution with actionable B2B insights to optimize your campaigns.